Sea-Tac firefighters and police were joined by first responders from 18 other agencies around the South Sound for a required drill for an airplane crash on Wednesday.

Using an old 757 fuselage mock up, the pretend scenario was the crash of a Boeing 737 with 150 people on board, just short and to the right of the airport's center runway.

The 757 and 737 bodies are the same width. Most volunteers are airport employees made up with fake injuries, some gruesome. Firefighters first on the scene go through the victims and mark them with tape to determine their priority for handling. Ambulances are soon on the scene to transport the victims to area hospitals sorted out with the help of Harborview Medical Center.

The drill now incorporates lessons learned from the last major airliner crash in the United States.

In 2013, an Asiana 777 crashed short of the runway at San Francisco International Airport. Three passengers, teenage girls from China were killed. But there were many injuries, most people getting off the plane before fire consumed much of the aircraft.

Sea-Tac's fire chief Randy Krause said changes this year include safer pathways into the scene.

In the 2013 Asiana crash, an airport fire truck ran over a victim covered up by firefighting foam. The goal was also to get firefighters to victims in the middle of the scene and quicker.

Flying has never been safer. There are more flights every day and accidents are exceedingly rare.

But just this week first responders are reminded why they do this realistic training.

Last Friday, also at San Francisco International Airport, an Air Canada Airbus 320 lined up to land on a taxiway with four other airliners sitting on it. The pilot pulled up and went around.

In Mississippi, a U.S. military C-130 crashed killing all 16 people on board.