NTSB Chairman Robert Sumwalt speaking at a media briefing said one passenger has died in the incident involving Southwest flight 1380.
He did not provide further details.
A Southwest flight was en route from LaGuardia Airport in New York City to Dallas Love Field when it was diverted to Philadelphia International Airport Tuesday.
Photos posted to social media showed the engine was damaged.
Passengers aboard Flight 1380 say a woman was partially sucked out of a broken window and had to be pulled back in.
“One passenger, a woman, was partially … was drawn out towards the out of the plane … was pulled back in by other passengers,” Todd Baur said in a phone interview with NBC10.
The Boeing 737-700 had 143 passengers onboard.
“We are aware that Southwest flight #1380 from New York La Guardia to Dallas Love Field has diverted to Philadelphia International Airport,” Southwest said in a statement. “We are in the process of transporting customers and crew into the terminal.”