Post you less than jolly factoids here, For example:
You know the infamous CCTV still of Klebold and Harris in the Columbine HS cafeteria, weapons at the ready? The one that the news often says shows the start of the attack, where it looks like Klebold is stalking around maniacally looking for victims while brandishing a TEC-9? Yeah... actually, at that point the whole event was almost over, and the two are just standing around talking; the last of the immediate fatalities (except the Dimwitted Duo) had been half an hour earlier. The angle gives the impression of motion, but they were just standing still. While it isn't sure what they were saying, based on the parts some of the injured overheard, they seem to have been calmly going over the best way to make an appropriately dramatic finale.
About two minutes later, they walked back to the library, where most of the stand off took place, only to find that the hostages had run off in their absence. After another ten minutes, during which they took some potshots at the police and (again, based on what some injured students still in the library overheard) complained about it not being as exciting as they'd hoped (!), they shot themselves in a rather anti-climactic fashion.
It took the authorities another three hours before they were willing to risk going in, during which time one of the injured - William David Sanders, the same teacher who ordered the students out of the caf at the start of things, and who is credited with saving most of them - died of blood loss (probably; they aren't sure if he was dead before the attackers killed themselves, it was fairly rapid either way so a faster response might not have mattered, but it just added to the criticisms of the police's actions that day).