KEY POINTS
  • One passenger was killed on Southwest Flight 1380 when a fan blade flew off the engine.
  • The airline is in the midst of an inspection of all of its engines' fan blades.
U.S. NTSB investigators are on scene examining damage to the engine of the Southwest Airlines plane in this image released from Philadelphia, Pennsylvania, April 17, 2018.

Southwest Airlines has sped up a sweeping inspection of its engines following a midair failure last week that killed a passenger, the airline's first fatal accident in its almost five decades of flying. But the engine parts that have been under the most scrutiny may not have been the only factor in the accident, a company executive said Thursday.

One of the fan blades on the Boeing 737-700 broke off during the New York-to-Dallas flight on April 17. After the blade broke off, shrapnel flew, puncturing the fuselage. A passenger, bank executive Jennifer Riordan, was partially sucked through a blown-out window, and died. But the engine also lost part of its cowling, which surrounds the engine's fan.