What if the bombs in the cafeteria exploded ?

The plan was that when the bombs exploded they were prepared to shoot at the fleeing survivors .

Do you think they would still go to the library if the plan worked ?

I think yes , they would .

The library massacre was one of the plans , thats why they went directly to the library after they entered the school and didnt waste time looking around the school .

I'm not sure it was part of the original plan. Wouldn't the library have fallen in if the cafeteria bombs would have done their job?

Radioactive_Clothing wrote:

I'm not sure it was part of the original plan. Wouldn't the library have fallen in if the cafeteria bombs would have done their job?

yes , you are right .

But the library was the plan b in case the bombs failed to explode .

afrrs wrote:

Radioactive_Clothing wrote:

I'm not sure it was part of the original plan. Wouldn't the library have fallen in if the cafeteria bombs would have done their job?

yes , you are right .

But the library was the plan b in case the bombs failed to explode .

I don't think they really had a 'plan b' as such and just assumed the bombs would work.

I guess they knew the library would be reasonably well populated and would be trickier to get to for law enforcement (assuming they thought they'd go straight in). Perhaps they would have thought about the main attack with guns in the cafeteria but feared being 'rushed' by the vast numbers in there so the library was the best bet.

From the Final Report:

The investigation determined that Harris and Klebold placed two 20-lb. propane tank bombs in the cafeteria the morning of April 20. Computer modeling substantiated by field testing indicated that had those two large 20-lb. propane bombs detonated with a cafeteria full of students, most would have been killed or severely injured by the resulting blasts and subsequent fireballs. There were approximately 488 students in the cafeteria at 11:17 a.m. on April 20, the time the bombs were set to detonate. In addition to the casualties caused by the explosions, the computer models demonstrated a strong likelihood of structural damage and partial collapse of the cafeteria and possible library above.

Radioactive_Clothing wrote:

afrrs wrote:

Radioactive_Clothing wrote:

I'm not sure it was part of the original plan. Wouldn't the library have fallen in if the cafeteria bombs would have done their job?

yes , you are right .

But the library was the plan b in case the bombs failed to explode .

I don't think they really had a 'plan b' as such and just assumed the bombs would work.

I guess they knew the library would be reasonably well populated and would be trickier to get to for law enforcement (assuming they thought they'd go straight in). Perhaps they would have thought about the main attack with guns in the cafeteria but feared being 'rushed' by the vast numbers in there so the library was the best bet.

According to Brooks' book the library was their groups lunch hangout in previous years, so they had to know that it would have a decent amount of people there. If I remember right both bombs were next to support columns which would imply Eric wanted the library to collapse downward. I know its speculated on that the library would have came down, but I've always wondered if that was the boys intent or not.

Nirvana92 wrote:

Radioactive_Clothing wrote:

afrrs wrote:

Radioactive_Clothing wrote:

I'm not sure it was part of the original plan. Wouldn't the library have fallen in if the cafeteria bombs would have done their job?

yes , you are right .

But the library was the plan b in case the bombs failed to explode .

I don't think they really had a 'plan b' as such and just assumed the bombs would work.

I guess they knew the library would be reasonably well populated and would be trickier to get to for law enforcement (assuming they thought they'd go straight in). Perhaps they would have thought about the main attack with guns in the cafeteria but feared being 'rushed' by the vast numbers in there so the library was the best bet.

According to Brooks' book the library was their groups lunch hangout in previous years, so they had to know that it would have a decent amount of people there. If I remember right both bombs were next to support columns which would imply Eric wanted the library to collapse downward. I know its speculated on that the library would have came down, but I've always wondered if that was the boys intent or not.

yes , the plan for them was that the bombs would destroy the cafeteria and the library above it .

afrrs wrote:

Nirvana92 wrote:

Radioactive_Clothing wrote:

afrrs wrote:

Radioactive_Clothing wrote:

I'm not sure it was part of the original plan. Wouldn't the library have fallen in if the cafeteria bombs would have done their job?

yes , you are right .

But the library was the plan b in case the bombs failed to explode .

I don't think they really had a 'plan b' as such and just assumed the bombs would work.

I guess they knew the library would be reasonably well populated and would be trickier to get to for law enforcement (assuming they thought they'd go straight in). Perhaps they would have thought about the main attack with guns in the cafeteria but feared being 'rushed' by the vast numbers in there so the library was the best bet.

According to Brooks' book the library was their groups lunch hangout in previous years, so they had to know that it would have a decent amount of people there. If I remember right both bombs were next to support columns which would imply Eric wanted the library to collapse downward. I know its speculated on that the library would have came down, but I've always wondered if that was the boys intent or not.

yes , the plan for them was that the bombs would destroy the cafeteria and the library above it .

Eric scouted the library, one of his documents that were released showcased his "research" on peak timing to blow up the commons.

I also read somewhere, a female friend caught them surveying things & grabbed Eric's notes playfully.

If the bombs in the cafeteria had exploded, there wouldn't have been a library anymore.

their original plan was that they would shot fleeing people after the bombs exploded. Do you think i am wrong with this? I think they wouldn´t go for the library.

em81 wrote:

their original plan was that they would shot fleeing people after the bombs exploded. Do you think i am wrong with this? I think they wouldn´t go for the library.

Of course they didnt specifically target the library because there weren't as many people there compared to the cafeteria. The bombs were placed in the cafeteria at lunch because it was the spot on campus with the highest density of people at a single time. They only entered the library because the bombs didnt detonate and they knew it was the second most populated area during lunch time. Had E and D known for sure that the bombs wouldn't detonate I'm sure they would have thought twice about attacking that day. 13 deaths is quite a ways off from the 250+ they had hoped for. I imagine Eric was more than a little pissed NBK didnt go the way he planned. All those pages of writings and hours of video he spent boasting and he didnt even come close to the damage he dreamed of. It was, to quote the kid himself, "Pathetic".

sororityalpha wrote:

From the Final Report:

The investigation determined that Harris and Klebold placed two 20-lb.  propane tank bombs in the cafeteria the morning of April 20.  Computer modeling substantiated by field testing indicated that had those two large 20-lb. propane bombs detonated with a cafeteria full of students, most would have been killed or severely injured by the resulting blasts and subsequent fireballs.  There were approximately 488 students in the cafeteria at 11:17 a.m. on April 20, the time the bombs were set to detonate.  In addition to the casualties caused by the explosions, the computer models demonstrated a strong likelihood of structural damage and partial collapse of the cafeteria and possible library above.

I have been looking far and wide for the source of this data. Does it mention who calculated this in the documents? I have several doubts relating to the collapse damage claim. That was a steel framed building with an entire wall of glass. Even if the bombs fully detonated, it would take out the windows, which would dissipate all of the explosive force. There would not have been any fuel source to provide for an extended burn to heat up any support structures either.

I think they would have still had a go at the library even if the bombs fully went off. IN fact, I think they would have been angrier since the explosion would have caused only localized casualties in the cafeteria, and not the school wide explosion that they were hoping for. Propane tanks are dangerous, but they've been engineered over the years to fail in distinct ways to protect people. Now, if you put a tank in a car trunk or other enclosed space, it will do a lot of damage. Not enough to level a building mind you, but enough to total a passenger car.

IDK... I don't think a propane bomb would reall do as much damage as they think. It would have made a nice boom, and fireball, but I don't think it would have blown off anything major.... Use a real case
Tim M. (Ok city bombing) he used hundreds of pounds and look at what he did, they would have had to made something more along the lines of what Tim did to create what they were after. They would have needed prolly 100lbs of that to bring down the library. I have been watching videos of propane tanks and they don't seem that aggressive when they go off.

Same here. It looks like the big ones do some damage when they go off. However, those are in your typical wood frame residential buildings. AFAIK, Columbine was all cement, steel and masonry.

deathmedic wrote:

IDK... I don't think a propane bomb would reall do as much damage as they think. It would have made a nice boom, and fireball, but I don't think it would have blown off anything major.... Use a real case
Tim M. (Ok city bombing) he used hundreds of pounds and look at what he did, they would have had to made something more along the lines of what Tim did to create what they were after. They would have needed prolly 100lbs of that to bring down the library. I have been watching videos of propane tanks and they don't seem that aggressive when they go off.

The propane tanks were surrounded by smaller gas cans, mini camping tanks, WD40 cans, and lots of shrapnel. All that would ignite as a mixture and create a blast, which would set off the even bigger propane explosion. The bombs were placed by support columns. Because of that the explosion didnt need to be strong enough to kill on its own. It just had to cause enough damage to those columns and collapse the library. Falling debris such as tables and bookshelves would have been capable of crushing multiple people underneath. Bomb experts determined the blast would have been capable of killing nearly everyone there had they detonated correctly.

Thats the thing, I can't find the experts who calculated that. If you look at the propane association website, they talk about tanks that have been in rollover collisions and suffered direct large caliber gunshots, and they still don't go off.


Not to mention, I couldn't find any other examples of exploding BBQ propane tanks collapsing other similar structures. Small, enclosed wood frame structures are a different story though.

There would be fatalities and severe trauma in the immediate vicinity of the propane bombs, but I'm still skeptical about a full collapse.

If the bombs had gone off, they would not have killed anyone at all and Eric and Dylan would've been shot by Gardner and Smoker soon after.

Eric and Dylan used a BLEVE device, which means that the bombs would've exploded in two steps, the first a small explosion that would have started a fire, and the second a much larger explosion brought about by that fire heating a propane tank, as you can see here.

If the bombs had gone off, the students would have witnessed a fireball, not an explosion. And in fact, Dylan successfully detonates one at 1:10 here, so you can see what the students would've seen if the bombs had gone off--a fireball which quickly dwindles into a very small fire.

Those fleeing the fireball out the southwest doors would've probably encountered Harris fairly soon. And he would've begun shooting. But because there are so many doors (and the fire would've been small), they all would've run right back into the cafeteria at the first shots.  Those fleeing through the northwest door would've encountered Dylan, but who knows what he would've done. He barely fired in the beginning as it was.

At this point, Eric and Dylan would have been standing outside right as Neil Gardner drove up and they would not have been together. Both would've been exposed to his weapon (in fact, Eric would've had his back to him) and we know that Gardner would not have been hesitant to shoot them.  

Another possibility is that Eric and Dylan would've pursued the students into the cafeteria. This might have led to a higher casualty count, especially if they had gone upstairs, where the students would at this point have been following fire drill protocol, but I don't believe they would've done it, because Eric was extremely scared of his own bomb. In fact, at the slightest sign that Dylan is about to detonate it Eric takes off running at 1:22 in the above video.

So I see the casualty count being lower, not higher, if the bombs had gone off.

Very nice assessment.

I agree that the propane bombs wouldn't have done very much damage. In the cafeteria footage, I always thought that was one of the outer cans exploding, and not a tank rupture. It just further reinforced my thoughts that the original estimation was way off. It still confuses me as to how they arrived at the conclusion that the building would have collapsed. My speculation is that one of the news outlets guesstimated that long ago, and everyone just ran with it.

Interestingly, Gardner already knew who Eric and Dylan were. After the complaints flied by Judy Brown, Deputy Gutierrez came to the school to ask Gardner about them, and how they were at school. Apparently they were "just a couple of misfit kids".

I can't imagine what was going through his head when he had to pull out his weapon and start firing at students.

I think that there would have been opportunity to rush and overtake the two shooters, especially Dylan. Not only was he more hesitant about firing outside, he also had at least one jammed magazine.

I think the more kids got outside, the fewer targets they would have had. That tec-9 was never gonna hit anything outside of fifty feet, and Eric's gun was never properly sighted in AFAIK. In fact, didn't Eric have a laser pointer or something attached to his gun? I recall an older thread, that he had crudely attached laser sight of some kind.

Jefferson County publicized the myth to make excuses. The bombs could've killed 400. Our officers had to move carefully.  Harris and Klebold were lethal terrorists.

The whole thing reads like a bad novel:

A pipe bomb had exploded and singed the carpet in front of them. Glass had shattered everywhere. Live ammunition rounds and spent casings were lying on the floor.

So obviously they are trying to exaggerate everything to make excuses for not getting to Dave Sanders or to the library. The bombs would've killed 400 thing is just another part of that.

i think it was only Erics and Dylans wish to 400 or 500 people, but like you all said, the bombs wouldn´t make a big damage. i don´t have much knowledge about bombs, so it´s only speculation.

Yeah, I'm no expert either. However, propane tanks are pretty well designed to be very safe even when they fail.

Quote :

And in fact, Dylan successfully detonates one at 1:10 here, so you can see what the students would've seen if the bombs had gone off--a fireball which quickly dwindles into a very small fire

Actually, what you are seeing is simply an explosion from a cricket/pipe bomb rupturing/igniting one of the gas containers catching fire.

None of the propane tanks/canisters actually exploded that day.

I see. Here is what 3 tanks looks like when they're ruptured.

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It's a big fireball and some shrapnel, but not enough to take down most structures.

I think propane tanks have a safety release on them too so the will not blow, it will og off and spray but not the big boom and carnage.

This reminds me of the King Of The Hill episode in which Buckley dies when he causes the Mega-Lo-Mart to explode by dragging the propane tanks around by their nozzles and causing leaks. That actually makes the trivia about the girl who was in love with E or D and wrote to Mike Judge after she saw the episode about Buckley's angel and it helpd her a little more creepy and make a little more sense - the boys wanted to use propane to blow up a building like Buckley did by accident.

Yeah, the fact of the matter is that propane tanks are probably the worst thing to make a bomb out of. If they had made a similar sized bomb, but it was the fertilizer style one like what was used in the Oklahoma City bombing, they would have probably done some damage.

However, the bomb that blew up the federal building was about 2000 lbs of fuel and fertilizer, AFIK. Eric and Dylan would only be able to manage about one tenth of that, but it would still be substantial.

This is similar to what he used (Not exactly the same but close), I can find a 12.5 pound video of exactly what Tim used but to give an idea of ANFO/ Vs propane... 1/10 (200 lbs) of it would have been enough to take down the school.
Ths is 50lbs of it.
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here is exactly what he used

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That 50 lb one is frightening. If they managed to bring in 200 lbs. of that, it would have done the job. Even if it didn't collapse the building, just the concussive force of the blast would have killed most of the people in the cafeteria.

I think it was eric idea to put the propane bombs , i think it was a late minute idea , they really didnt think it well enough , obviously the clocks that they put there to trigger the explosion was poorly executed . Btw , it was eric that was reading the anarchist cook book .

I really wonder how much time they had really dedicated to planning and testing out their stuff. It couldn't have been much, because most of their stuff didn't work or 1/2 assed worked. I mean if I had planned out something for a year I would make sure what I was going to do worked when it came down to it. But we are talking about teens that think they know better than anyone else.

From the BT, it looks like they were still figuring out the timers. Eric mentioned going to Radio Shack to pick up some kind of amplifier or circuit relay.

Also, is there a firm description of the diversionary bombs they built? I recall another Columbine forum that mentioned the guy who found it. When he triggered it inadvertently, it made a whirring noise like an RC car.

sororityalpha wrote:

Quote :

And in fact, Dylan successfully detonates one at 1:10 here, so you can see what the students would've seen if the bombs had gone off--a fireball which quickly dwindles into a very small fire

Actually, what you are seeing is simply an explosion from a cricket/pipe bomb rupturing/igniting one of the gas containers catching fire.

None of the propane tanks/canisters actually exploded that day.

Yes, that is exactly what I am saying. The bombs were designed to explode in two stages--first a flammable container of gas that would heat the propane bomb, and then the propane bomb some minutes later.

If the timer had worked, it would have first created a fireball like the one you see in the video at 1:10--a fireball which quickly would've dwindled into a small fire.

The 2 car propane tank bombs were connected to pipe bomb(s) + gasoline as well.


The plan may have been: simultaneous -- pipe bomb explosion + gasoline/kerosene ignition + rupture in the propane tank(s) = the BIG explosion.

If all 3 happened at the same time, there would not have been a BLEVE but a massive explosion.


**Using pipe bombs in association with the propane tanks indicates that Eric/Dylan were hoping to rupture the tanks and not simply heat them up waiting for them to explode.

Gasoline tends to make a pretty decent explosion. However, you need to confine that explosion within a smaller, sturdy enclosure for it to do damage. The enclosure pressurizes, and then fails giving off both a shock wave as well as a bit of shrapnel. There is a fireball, but it dissipates quickly.

When you see cars explode on TV, they tend to rupture at the windows first. This is the weakest point, and then dissipates the rest of the explosion. Any large explosion in the cafeteria, especially any explosion with dense, metal shrapnel, would have destroyed the large wall of windows. This would have expelled most of the shock wave and the fire ball would have followed that as the path of least resistance to fuel(air) as well.

The pipe bombs would most likely do nothing to the propane tanks. There have been instances where similar tanks have been set fire to or shot at and nothing happens. Entire propane delivery trucks have had rollover accidents at freeway speed, and still stayed intact with no punctures. I understand their intent, but their means would have never achived their goal

radaddio wrote:

Gasoline tends to make a pretty decent explosion. However, you need to confine that explosion within a smaller, sturdy enclosure for it to do damage. The enclosure pressurizes, and then fails giving off both a shock wave as well as a bit of shrapnel. There is a fireball, but it dissipates quickly.

When you see cars explode on TV, they tend to rupture at the windows first. This is the weakest point, and then dissipates the rest of the explosion. Any large explosion in the cafeteria, especially any explosion with dense, metal shrapnel, would have destroyed the large wall of windows. This would have expelled most of the shock wave and the fire ball would have followed that as the path of least resistance to fuel(air) as well.

The pipe bombs would most likely do nothing to the propane tanks. There have been instances where similar tanks have been set fire to or shot at and nothing happens. Entire propane delivery trucks have had rollover accidents at freeway speed, and still stayed intact with no punctures. I understand their intent, but their means would have never achived their goal

thats why im saying it was a plan that they didnt give much attention .

I agree. At best, I think it was just an optimistic goal for Eric.

sororityalpha wrote:

The 2 car propane tank bombs were connected to pipe bomb(s) + gasoline as well.


The plan may have been: simultaneous -- pipe bomb explosion + gasoline/kerosene ignition + rupture in the propane tank(s) = the BIG explosion.

If all 3 happened at the same time, there would not have been a BLEVE but a massive explosion.


**Using pipe bombs in association with the propane tanks indicates that Eric/Dylan were hoping to rupture the tanks and not simply heat them up waiting for them to explode.

My point is that 400 people and bringing down the cafeteria was not possible with what they carried into the commons. There was no way to make that set of items do that.

What was possible is the gasoline canisters going up in a fireball, which would have scared the students in the cafeteria but not ruptured the tank. So if the bomb HAD worked that's all that would have happened--a fireball, not an explosion killing 400 people. That was never in the cards and has always been exaggerated for political purposes.

The absolute, worst case scenario for those tanks would have been a dual burst of fire and some light shrapnel. There is a video I linked up above where a guy shoots three of them in a row. He's only about 100 feet away, and suffers no injury.

They wanted to kill as many people as they could, they knew the library would be pretty populated. They didn't waste their time stopping at each classroom, they wanted to kill a lot of people in a short amount of time before law enforcement came for them.

I think if the bombs went off as planned they wouldn't have needed to go inside at all, let alone go to the library.