The terrifying engine loss on a Southwest flight may have been caused by a fan blade that broke off from one of the two engines, per the Philadelphia Inquirer.

Why it matters: Less than a year ago, the FAA and the engine’s manufacturer drew attention to problems with metal fatigue on the fan blades in the CFM56 engine series, which this plane has, after a similar incident in 2016, also a Southwest plane.

• The NTSB said at a briefing in Philly, where the N.Y.-to-Dallas flight made an emergency landing, that the blade broke near where it connected to the engine’s hub, and there was evidence of metal fatigue.
• "One passenger, identified as Jennifer Riordan of Albuquerque, N.M., was rushed to an area hospital, where she died ... She was a vice president of community relations with Wells Fargo and a married mother of two. Officials did not explain how she died."
• "The flight was carrying five crew members and 144 passengers, some of whom described hearing a loud boom in mid-flight before a window blew out and the smoke-filled plane suddenly dropped."
• "The failure happened at 32,500 feet."
• Reuters: "The CFM56 engine was produced by a joint venture of GE and France’s Safran SA called CFM International and is one of the most common engines, paired with the world’s most-sold plane, the Boeing 737."

"Passenger Matt Tranchin, 34, of Dallas, told reporters that flight attendants and some passengers worked to cover the hole in the plane.

• “I spent a lot of my time trying to articulate what my final words would be ... to our unborn child, to my wife, to my parents.”