Investigators say a missing piece from an Alaska Airlines jet that blew off on Friday at 16,000 feet has been recovered in Oregon.
The National Transportation Safety Board said having the door plug will help determine why it peeled away from the plane shortly after taking off from Portland International Airport, leaving a gaping hole in the side of the fuselage.
The flight bound for Ontario, California, returned safely to the airport.
Federal regulators toured the plane, both inside and around it, and they described it as a very close call. The door plug is roughly the size of a refrigerator. The plug was found after an Oregon teacher called authorities to report spotting it in his backyard.
Investigators say the same aircraft had an air pressurization light go off on three previous flights in recent weeks. Because of this, it was banned from flying over the ocean, but the problem wasn't fixed and Alaska Airlines decided not to take the jet out of service.
"It was very much described as benign," said NTSB Chair Jennifer Homendy. "They did order an additional maintenance look at that light. That was not completed before the time of this event."
FAA grounds Boeing 737 Max 9 after plane wall detached midair
It is not immediately known how that will affect flight schedules for airlines with the specific jetliners in their fleet.
Investigators say it is unclear whether any of the issues with the air pressurization light were actually related to the door plug.
No one was seated in the two seats directly next to the section of the plane that blew off. Homendy said of the 178 seats on the plane, 171 were occupied.
Friday's incident led to the nationwide grounding of certain Boeing 737 Max 9 aircraft, followed by a number of flight cancellations.
Flight attendants checked on children amid chaos
As the flight returned to Portland International Airport, Homendy said the flight crew and attendants took "heroic" actions to save lives.
Homendy noted that there were three infant children on board being held in their parents' laps. She also noted that there were four unaccompanied minors on the flight.
"The flight attendants were very concerned for their safety, very focused on whether they had their masks and whether they were secured," Homendy said.
"After this explosive event occurred, suddenly, the flight attendants were very focused on what was going on with those children. Were they safe? Were they secure? Did they have their lap belts on and did they have their masks on? And they did."
Homendy said that the door to the cockpit flew open during the incident. It took three attempts by the flight attendant to shut the door, Homendy said.
Homendy said the flight attendants struggled to communicate with the flight deck. Yet their actions and training kicked in to keep people from being injured.
"The actions of the flight crew were incredible," Homendy said. "It was described as chaos, very loud between the air and everything going on around them, and it was very violent when the rapid decompression in the door was expelled out of the plane. There was a lot going on and I just really want to thank the actions of the flight crew that was equally heroic. The flight crew entirely did an excellent job."
