An Alaska Airlines flight from Oregon to Southern California made an emergency landing Friday following a mid-air incident in which part of a side of the plane appeared to have detached.

Flight 1282 landed safety at Portland International Airport, Port of Portland spokesperson Allison Ferre said in a statement.

No injuries were reported among the 174 passengers and 6 crew members on board, Alaska Airlines said.

The Federal Aviation Administration said it returned to the airport after "the crew reported a pressurization issue."

Alaska described what happened as an "incident." A photo from a passenger on board showed an entire panel missing from a side of the fuselage, next to a row of seats.

It’s not clear how or when the panel became separated from the passenger jet.

On Saturday, the airline said it would temporarily ground all 65 of its 737 Max 9 aircraft while it conducts maintenance and safety inspections.

Kyle Rinker posted a photo from inside the plane on social media platform X, along with the caption, “When the wall of the plane just breaks off mid flight.”

A passenger on the plane who gave her name only as Elizabeth told NBC affiliate KGW of Portland, Oregon, that the incident happened about 20 minutes after departing Portland’s airport.

“Everything was going fine until we just heard like a loud bang! Or like a boom,” she said. “And I look up, and the air masks are, like, out, popped down.”

“And I looked to my left, and there’s just this huge gaping hole, on the left side where the window is,” she told the station in a phone interview. She said the sound of the wind was very loud.

She said everyone had their seat belts on and people stayed calm, she said.

Alaska said in a statement, “The safety of our guests and employees is always our primary priority, so while this type of occurrence is rare, our flight crew was trained and prepared to safely manage the situation.” 

The flight was destined for Ontario International Airport in San Bernardino County, California.

According to FlightAware, an air travel tracking site, the flight took off from Portland at 5:07 p.m. and landed back at Portland at 5:27 p.m.

It identified the aircraft as a Boeing 737 MAX 9.

Boeing said in a statement that it was aware of the incident.

"We are working to gather more information and are in contact with our airline customer," it said. "A Boeing technical team stands ready to support the investigation.”

Secretary of Transportation Pete Buttigieg said on X Saturday morning that he has "been briefed on last night’s incident and remain in close contact with FAA on the response."

The FAA and Alaska Airlines both said they were probing the incident. The National Transportation Safety Board has launched a Go Team to Portland to investigate the incident.