An American Airlines plane has caught fire in Chicago with passengers aboard.

The right-side engine of the Boeing 767 failed Friday during an attempted takeoff, sending debris as far as a half mile and passengers hurriedly down emergency slides onto a runway at Chicago’s O’Hare International Airport.

According to CNN, three sources familiar with the unfolding investigation revealed that the General Electric engine suffered an apparent “uncontained” failure.

The 161 terrified passengers and nine crew members scrambled to safety Friday afternoon after huge flames erupted on the right side of the plane.

Airport fire Chief Timothy Sampey said crews responded to a report of a No. 2 engine on fire. The plane, which had stopped well before the end of the runway, had about 43,000 pounds of fuel.

“This could have been absolutely devastating if it happened later,” he said.

About 20 people were taken to the hospital with minor injuries that occurred during the evacuation down the emergency slides, District Chief Juan Hernandez said. There were people with minor bruising or injured ankles, he said. None of the injuries were caused by the fire.

American Airlines spokeswoman Leslie Scott said Flight 383 was bound for Miami when it aborted takeoff due to an engine-related issue.

The rare, but extremely serious, engine failure sent debris from the engine spewing across the south side of the expansive airfield. Part of the engine’s fan disc were found a half mile away on a building used by UPS, two sources said.

A passenger who was sitting in the middle of row 31 said he heard a loud clunk, then saw a large ball of flame that he assumed came from the engine area. Gary Schiavone of DeMotte, Indiana, said the captain was able to stop the aircraft quickly, and then it was “coordinated chaos.”

Here’s another video of the @AmericanAir plane in Chicago. pic.twitter.com/FCufW3BzDQ

— Jose Castillo ? (@Kryptonlogic) October 28, 2016

There wasn’t much yelling or screaming, he told reporters, except passengers who shouted at others who were trying to grab their bags from the overhead bins. Schiavone said about 30 seconds into the evacuation, smoke started to pour into the cabin.

The difficulty in breathing was the scariest part, he said.

Asked whether he was afraid he was going to die, Schiavone said, “Of course. I’m thinking the plane is going to blow up.”

Schiavone complimented the crew for getting everyone out in what he estimated was about a minute.