via.kdvr.com
Delta Air Lines identifies cause of smoke on evacuated flight
DENVER -- Delta Air Lines has identified what caused a plane to fill with smoke at Denver International Airport on Tuesday night, prompting the evacuation of more than 140 passengers and crew. The airline says a small amount of hydraulic fluid dripped onto the aircraft's auxilary power unit. That's a small jet in the back of the plane. It's typically activated after a plane lands as a way to generate electricity.