A landing feature was “inoperative” on a passenger plane that slid off a runway in the US state of Florida on Friday, investigators have said.
The Boeing 737, operated by Miami Air International, ended up in a river after landing during a thunderstorm.
Officials said 21 people were taken to hospital with minor injuries, and at least four pets kept in the hold died.
They are now looking into the failure of the “thrust reverser”, as well as a request by the pilot to change runways.
The flight, which had flown from Guantanamo Bay in Cuba to a military base in the city of Jacksonville, is said to have landed heavily in the storm before skidding into St John’s River.
The 136 passengers and seven crew members on board evacuated the Boeing 737-800 via its wings.
“The aircraft had been in maintenance and the maintenance log noted that the left-hand thrust reverser was inoperative,” Bruce Landsberg, vice-chairman of the US National Transportation Safety Board, told a press conference on Sunday.
Mr Landsberg added that shortly before they landed, the pilots had asked to change to a runway which had equipment set up on it, and which therefore had less space available.
“We don’t know what they were thinking or why that was their choice,” he said.
He also confirmed that several dogs and cats traveling in crates in the cargo hold were presumed to have drowned and that the US Navy has arranged for divers to recover their bodies from the plane.bbc