The U.S. National Transportation Safety Board has sent a so-called go-team to Philadelphia International Airport to investigate an uncontained engine failure that killed a passenger aboard a Southwest Airlines Boeing 737-700 on Tuesday. The engine, a CFM56-7B, exploded at about 11:30 a.m. as the airplane carried 148 people on a flight from New York La Guardia Airport to Dallas Love Field, shedding shrapnel that shattered a window and killed the passenger. The death was the first aboard a U.S. airliner in more than nine years, NTSB chairman Robert Sumwalt said at a press conference in Philadelphia. The FAA lifted a ground stop imposed at the airport at about 1:45 p.m.

The incident appears reminiscent of an uncontained failure in 2016 of another Southwest Airlines 737-700, one of whose CFM56s exploded during a flight from New Orleans to Orlando, Florida. In that case, the NTSB determined that a fan blade separated from the fan disk during the flight due to metal fatigue. Although engine debris created a 5-inch by 16-inch hole in the fuselage just above the left wing, none of the debris penetrated the passenger compartment.