Officials with the National Transportation Safety Board are briefing the public and media with the latest information related to the hole that opened mid-air in the fuselage of an Alaskan Airlines flight bound for Southern California out of Portland, Oregon Friday.  

Alaska Flight 1282 departed PDX around 5 p.m. and was airborne for about 20 minutes when passengers reported hearing a “loud boom.” 

“The oxygen masks dropped down, and I look to my left to hear and see wind blasting, with a piece of the wall gone,” Elizabeth Le told KTLA. 

The airline said that the pilot immediately turned around the Boeing 737 Max 9, which was carrying 171 passengers and six crew members, and returned to Portland where it landed safely. 

FlightAware, a website that tracks flights, showed the jet reached an altitude of about 16,000 feet before descending rapidly and circling back to the airport. 

The cause of the mishap was not immediately known, though according to the Associated Press, investigators with the NTSB on Sunday were searching for a piece of fuselage that blew off the airliner in hopes of getting physical evidence of what went wrong.  

The gaping hole that opened in the side of the jet was located in the spot where Boeing, the aircraft manufacturer, “fits a ‘plug’ to cover an emergency exit that the airline does not use,” the AP reported.  

United Airlines and Alaska grounded its fleet of 737 Max 9 jetliners while they waited to be told how to inspect the aircraft to prevent future mid-air blowouts.

NTSB Chair Jennifer Homendy will be holding the briefing in Portland.

This article is currently being updated.