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.

The National Transportation Safety Board releases probable cause on midair door plug blow out on Alaskan Airlines Flight.

The National Transportation Safety Board found Boeing and the FAA responsible for "multiple system failures," leading to Alaska Airlines' door blowing off mid-flight last year near Portland, Oregon.