A fire on an airplane is never ever going to be a good thing, but at least in the case of a United Airlines plane at Seattle’s Sea-Tac Airport this weekend, the fire occurred before the plane took off and all passengers were safely evacuated.

The flight was set to head to Washington, D.C. on Saturday night. An airport spokesman said the Seattle Fire Department responded to the fire at 10:27 p.m. Firefighters discovered flames coming from the auxiliary power unit of the Boeing 757 that was supposed to take off at 10:30.

The fire crew put out the flames and everyone was safely evacuated off the plane, reports the Seattle Times. As for what could’ve caused the fire, officials think it could have been due to residual oil in the power unit, which is in the plane’s tail. The plane was towed away so investigators can get down to the bottom of what caused the fire.

Originally, the plane had come in from Chicago’s O’Hare International Airport earlier that day. Passengers were scheduled to be put on another plane leaving before midnight.

United plane at Sea-Tac catches fire before takeoff; all passengers evacuated safely [Seattle Times]

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