William “Dave” Sanders

On April 20th, 1999, Eric Harris and Dylan Klebold terrorized their school, Columbine High School, by opening fire on students and staff after their placed bombs failed to detonate. Before the two perpetrators committed suicide nearly an hour after starting their attack, they killed 12 students and one teacher, and left 24 injured.
The death toll likely would have been much higher if it weren’t for William “Dave” Sanders, a teacher at the school that realized before many others that this was not a senior prank.  He ran through the cafeteria (above) to warn students to run and hide before the two could find them. This proved beneficial because the cafeteria was their main target.
As Sanders ran out of the cafeteria to warn other students, he ran into Klebold and Harris in the hallway, where he was shot twice and died before first responders were able to reach him. He was the only teacher killed that day.

Concorde Air France Flight 4590

On July 25th, 2000, Air France Flight 4590 took off from Paris and set its sights for New York when it struck runway debris, causing the plane to blow a tire and puncture a fuel tank upon takeoff. The engine burst into flames shortly before it failed and the plane crashed into a hotel soon after.
All 100 passengers and 9 crew members died from the tragedy, and this is the last photo snapped immediately after the plane took off, evidence that the damage was serious from the start. An additional 4 people were killed from the ground and several others were critically injured.