The Bombs
The Columbine Attack

Eric Harris and Dylan Klebold planned Columbine primarily as a bombing. The timers were set to begin with the eruption of two big propane bombs in the cafeteria at 11:17 a.m. That was the start of "A" lunch, the maximum human density anytime, anywhere in the school on any given day. Maximum body count.

 

Eric and Dylan then intended to open fire at fleeing survivors (guns here). They also loaded their cars with bombs and gasoline, set to detonate about noon.

 

These are the official Jeffco sheriff's photos of the big bombs. All failed. (Only the pipe bombs worked. The "diversion" bomb in a field ignited its detonator and started a grass fire, but also failed to explode.)

 

Explanations appear below the photos.

Columbine bomb summary explosives

Screen print from the bomb summary pages of the JeffCo Sheriff's Department's official report. Read more here.

Columbine bomb's placed in cafeteria

Another screen print from the bomb summary pages of the JeffCo Sheriff's report. These are a great intro.

Columbine cafeteria propane bomb--duffel bag burned by Dylan's Molotov Cocktail

One of the two big propane bombs in the cafeteria. The timing device is to the left. (This is how it was found. Its duffel bag was burned away by the Molotov Cocktail Dylan Klebold threw at it trying to set it off, late in the attack. Eric Harris also fired at it with his rifle.)

Columbine cafeteria propane bomb gas can, clutter from panic

The second big propane bomb in the cafeteria. You can see the gasoline can as part of the bomb. The mess left during the panic is also captured well here. (The yellow cards are evidence markers, added by Jeffco.) 

Columbine cafeteria propane bombs clock timer Westclock Duracell

Timing device from one of the cars, employing a 9V Duracell battery, set to noon.

Columbine pipe bomb Eric Harris

One of Eric Harris's pipe bombs, lodged in a wall, with evidence marker.

Columbine propane bomb car, explosive clock incendiary device

This slide and the following show the car bomb explosives, at various stages of disassembly by Jeffco. (Eric Harris and Dylan Klebold didn't bother to rig everything together. The main device in each car was supposed to set it off and erupt the big jugs of gasoline, etc.)

Columbine propane bomb car, explosive clock incendiary device gasoline tanks
Columbine propane bomb Dylan's car, explosive