(PORTLAND, Ore.) — An Alaska Airlines flight returned to Portland, Oregon, soon after takeoff after it “experienced an incident,” prompting the airline to temporarily ground its Boeing 737-9 fleet, the airline said Friday.

Six crew members and 171 passengers were on board Flight 1282 bound for Ontario, California, the airline said.

The cabin became depressurized shortly after takeoff and the pilots asked for an emergency landing, according to the transcript of an air traffic control call from LiveATC.net. A photo posted on social media appeared to show a hole in the fuselage next to a passenger seat.

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

CEO Ben Minicucci called the grounding “precautionary,” saying in a statement the 65 planes will return to service “only after completion of full maintenance and safety inspections.”

“We are working with Boeing and regulators to understand what occurred tonight, and will share updates as more information is available,” Minicucci said.

As of Saturday morning, more than a quarter of inspections on the Alaska Airlines’ Boeing 737 MAX 9 fleet are complete with “no concerning findings,” the carrier said.

Alaska said planes will continue to return to service as inspections are completed.

“We deeply apologize to our guests whose flights have been impacted,” the airline said in a statement. “Guests whose travel has been impacted can go online to view flight options and rebook travel, place the value of their ticket in their Mileage Plan Wallet for future use, or request a refund.”

The damage that led to the emergency landing appeared to be in the location of a “plug,” said John J. Nance, an ABC News aviation analyst. Those are spots in the fuselage shaped similar to a door that aren’t designed to open, even when the aircraft is on the ground. They could be converted to doors if the airline needs an extra boarding door.

The Boeing 737 MAX 9 has been in service since October 2023, according to Federal Aviation Administration records.

The aircraft maker said it had a technical team standing ready to help with the investigation.

“We are aware of the incident involving Alaska Airlines Flight 1282,” Boeing officials said in a statement. “We are working to gather more information and are in contact with our airline customer.”

The National Transportation Safety Board said on Saturday they were sending a “go team” to Portland to investigate the incident.

The team will arrive on scene later Saturday and consists of experts in structures, operations and systems, the NTSB said.

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