What would Columbine have looked like if only Eric did it?

So I don't know if this has been discussed already on here so if it has forgive me. Say in an alternate universe Eric never meet Dylan/or they remained friends but Eric decided he couldn't trust Dylan of ruining his plans and did NBK alone, what would have happened if, just like in reality, the bombs don't go off, but Eric goes to plan b like they also did in reality but he's doing it alone, how would Eric commit it by himself?

I don't think he had the capacity to do it alone. Neither did Dylan.

Ivan wrote:

I don't think he had the capacity to do it alone. Neither did Dylan.

yeah, i think they were each a part of the other's motivation

Agree with the other 2 posters. Columbine on April 21, 1999 would have looked exactly as it did on April 19, 1999, because no attack would have occurred on the 20th.