1999 April 20th. Colorado, Littleton, Columbine High School: the most violent school assault in U.S. history Two students, 17 and 18 years old, fired more than 1,000 rounds of ammunition and detonated 30 explosive devices during their rampage. 12 persons were killed, 24 students were injured, some of them critically, 160 patients had to be triaged, and more then 2000 people had to be evacuated during the shooting. In the aftermath of the violence more than 60 other live explosives were found in and around the school.

At 11:21 AM first calls came in the 9-1-1 center reporting explosions and shots fired as well as multiple victims inside and outside the school.

The Littleton Fire Department responded initially with ALS-engine #11, two Rescue Ambulances # 11 + 13, and a Battalion Chief. They did not enter the immediate area and staged nearby until clearance by law enforcement officers. Additional ambulances (ground and air) were requested.

The first arriving units encountered total chaos. Hundreds of children were running away from the school in different directions, while other bystanders were running towards the school building.

In the following 45 minutes, police and SWAT (special weapons and tactics) teams, ambulances, and other emergency units arrived from multiple jurisdictions. There was no scene control in the initial phase, vehicles were blocking each other and the overwhelming extent of responding became a logistical problem.

In addition because of the size of the school building and the number of nearby streets in the direct line of fire, coordination was a challenge. In one instance, ambulances were motioned to stay away from a particular site, while other police officers flagged rescue crews to the very same spot.

Ambulance and fire vehicles were often used as shields between the teenage shooters and injured children. In at least one case, paramedics carried out rescue missions while police and assailants were exchanging gunfire.

Due to its size, Columbine High School provided many different escape routes, therefore, victims were found at several locations. An important lesson to be learned is that shooting events need flexible approaches. Be prepared to establish several triage-areas and to provide them with sufficient supplies, equipment, and manpower.

In the end, 12 persons were killed, 24 students were injured, some of them critically, 160 patients had to be triaged, and more than 2,000 people had to be evacuated during the shooting.