After a year and half of investigating, the top U.S. aviation investigator formally determined that Boeing and its chief regulator were to blame for the Alaska Airlines blowout.

Boeing (NYSE:BA) failed to provide adequate training, guidance and oversight to prevent the midair cabin panel blowout in a new 737 MAX 9 flight in January 2024, the National Transportation Safety Board said Tuesday,

The first six minutes of the flight to Southern California’s Ontario International Airport were routine. The Boeing 737 Max 9 was about halfway to its cruising altitude and traveling at more than 400 mph (640 kph) when passengers described a loud “boom” and wind so strong it ripped the shirt off someone’s back.