Female passenger killed as US flight makes emergency landing

A female passenger was killed after a US flight made an emergency landing in Philadelphia city due to engine failure, authorities said.

The Boeing 737-700, operated by Southwest Airlines, was flying from New York City to Dallas on Tuesday when one of its engines failed, reports Xinhua news agency.

Passengers said the plane was able to land "safely", and initial reports said one person, who was hurt by crashed window, was taken to hospital.

US National Transportation Safety Board (NTSB) Chairman Robert Sumwalt later confirmed one passenger had died from the accident.

Southwest Airlines said in a statement that 143 travellers and five crew members were on the flight.

Photos shared on social media by passengers showed the engine was badly damaged. Local news reports said the damage was caused by an explosion.

According to multiple accounts, passengers on board the plane went through terrifying moments as the plane dived, and some were said to be crying or vomiting.

The Philadelphia fire department said at a press conference the plane came down "in a fairly rapid manner", and preliminary examination of the flight record showed the aircraft dropped 5.2 km in five minutes.

A passenger made a brief Facebook live on his account at the final moments of the flight, saying "Engine exploded in the air and blew open window three seats away" from him.

The NTSB has announced an investigation into the incident.

All air traffic at Philadelphia was put on hold.