A Southwest Airlines jet with part of an engine cover ripped off and a damaged window made an emergency landing at Philadelphia's airport on Tuesday, leaving one passenger dead.Southwest flight 1380, a Boeing 737, encountered a problem with the engine shortly after take-off from New York's LaGuardia airport, Robert Sumwalt, chairperson of the National Transportation Safety Board, told a news conference.There was one fatality, he confirmed."We are saying this is an engine failure," Sumwalt said, confirming that parts flew out of the engine, which witnesses said hit a jet window, seriously injuring a woman. The identity of the dead person was not immediately disclosed.Seven passengers were treated for minor injuries according to officials.Southwest said there were 143 passengers and five crew members on board the Boeing 737, which was headed from New York's LaGuardia Airport to Dallas' Love Field. Most passengers walked off the plane onto the tarmac at the airport after landing around 11:20.Passenger Amanda Bourman said she saw emergency medical workers using a defibrillator to help a woman who was taken off the plane after it landed. The woman's condition wasn't immediately known.According to reports a woman was partially sucked out of the plane after shrapnel from the engine broke a window of the plane where she was seated in.The New York resident said she was seated near the back of the plane and was asleep when she heard a loud noise. She said the plane was fairly quiet because everyone was wearing an oxygen mask, while some passengers were in tears and others shouted words of encouragement.The FAA said that the plane landed after the crew reported damage to one of the engines, along with the fuselage and at least one window.The Philadelphia airport tweeted that Flight 1380 "landed safely at PHL and passengers are being brought into the terminal." No other details were given. Passenger Marty Martinez did a brief Facebook Live posting while wearing an oxygen mask. He posted, "Something is wrong with our plane! It appears we are going down! Emergency landing!! Southwest flight from NYC to Dallas!!"After the plane landed, he posted photos of a damaged window near the engine. News helicopter footage showed damage to the left engine and the tarmac covered with firefighting foam, although there were no signs of flames or smoke.Tracking data from FlightAware.com shows the flight was heading west over New York's southern tier when it abruptly turned toward Philadelphia.Southwest has about 700 planes, all of them 737s, including more than 500 737-700s like the one involved in Tuesday's emergency landing.It is the world's largest operator of the 737. The Boeing 737 is the best-selling jetliner in the world and has a good safety record.John Goglia, a former NTSB member, said investigators will take the Southwest engine apart to understand what happened and will look at maintenance records for the engine."There's a ring around the engine that's meant to contain the engine pieces when this happens," Goglia said. "In this case it didn't. That's going to be a big focal point for the NTSB — why didn't (the ring) do its job?"Goglia said the Boeing 737 is a safe plane but engine failures occur from time to time."We're pushing the engines to produce as much power as possible," he said. "We're right on the edge. Sometimes they fail, and that's why the containment ring is there."The engine failure was reminiscent of a similar event on a Southwest Boeing 737-700 jet in August 2016 as it flew from New Orleans to Orlando, Florida. Shrapnel from the engine left a 5-by-16 inch hole just above the wing. Passenger oxygen masks dropped from the ceiling. Pilots landed the plane safely in Pensacola, Florida.Investigators with the National Transportation Safety Board said one of the engine's fan blades broke off from the hub during the flight. The broken edge of the blade showed crack lines consistent with metal fatigue.The NTSB was sending a go-team to the airport in Philadelphia to investigate and planned a 3 p.m. news conference.