A disk in an engine turbine on a Boeing 767 failed before the American Airlines plane caught fire on Friday at O'Hare International Airport.
The fire on the Miami-bound plane was caused by an "uncontained" engine failure, which means pieces were blown out of the engine as the plane was taking off, federal officials said.
The cause of the failure on the right engine was not immediately known, said Lorenda Ward, a senior investigator in charge with the National Transportation Safety Board.
At least 20 people were taken to area hospitals for treatment of minor injuries related to escaping the plane on inflatable slide chutes, officials said. Those injured were released from hospitals Saturday, officials said.
Footage from the scene showed the Boeing 767, which appeared to be damaged on its rear and along its right side, sitting on the runway with flames underneath and shooting from one side along with plumes of smoke. The right wing was drooping toward the ground and appeared to have partially melted.
Passenger Sarah Ahmed told the plane had been speeding down the runway when she heard an explosion and saw flames and black smoke. She said everyone on the right side of the aircraft jumped from their seats and moved to the left side.
“People are yelling, ‘Open the door! Open the door!’ Everyone’s screaming and jumping on top of each other to open the door,” Ahmed said. “Within that time, I think it was seven seconds, there was smoke in the plane and the fire is right up against the windows, and it’s melting the windows.”
Passengers came down emergency slides, hurrying across grass next to the runway as emergency vehicles surrounded the plane.
Buses were sent to pick up the passengers and bring them back to the terminal, the airline said. The passengers were to be placed on another flight to Miami Friday evening.
The Federal Aviation Administration, which is investigating, said in a statement that the plane made an emergency stop around 2:35 p.m. after experiencing a problem during takeoff. An earlier FAA statement said the plane had blown a tire.