A woman has been killed and seven others needed medical treatment after an engine on a US passenger jet apparently exploded in midair.
Southwest Airlines Flight 1380 made an emergency landing in Philadelphia after a window, wings and fuselage were damaged in the incident, officials say.
In an air traffic control recording, one of the pilots can be heard saying “there is a hole and someone went out”.
The last passenger death on a US commercial flight was in 2009.
The Boeing 737-700 had been en route from New York’s La Guardia airport to Dallas, Texas, with 143 passengers and five crew when the incident happened on Tuesday morning.
Witnesses say an engine on the plane’s left side blew, smashing a window and causing cabin depressurisation that nearly sucked a woman out of the aircraft.
She was pulled back in by other passengers.
The plane made a safe landing at 11:20 (15:20 GMT), fire officials said.
Asked if the plane is on fire, she says it is not but adds: “They said there is a hole and someone went out.”
The US Federal Aviation Administration has opened an investigation.
The National Transportation Safety Board (NTSB) said a preliminary investigation had revealed that an engine fan blade was missing and there was evidence of metal fatigue at the point where it had apparently broken off.
NTSB Chairman Robert Sumwalt said part of the cowling – the engine’s covering – was found in Bernville, Pennsylvania, about 70 miles (112km) from Philadelphia.
Philadelphia Fire Commissioner Adam Thiel told a news conference that passengers and crew “did some pretty amazing things under very difficult circumstances”.
First responders “found a fuel leak and small fire in one of the engines”, he said, adding that they used foam to extinguish the flames.
Images have been shared on social media showing passengers sitting in oxygen masks as the plane shudders around them.
“All of a sudden, we heard this loud bang, rattling…” said one passenger.
Passenger Marty Martinez posted a brief Facebook live with the caption: “Something is wrong with our plane! It appears we are going down! Emergency landing!! Southwest flight from NYC to Dallas!!”
After landing, he told CBS News that it felt like the plane was “free-falling”, and added that he saw one injured woman being taken off the plane by rescuers.
“There was blood everywhere,” he said.
“First there was an explosion and then almost immediately the oxygen masks came down and probably within a matter of 10 seconds the engine hit a window and busted it wide open.”