The Alaska Airlines Boeing 737 Max 9 returned to Portland 35 minutes into its flight to California after an outer section, including a window, fell, reported BBC.

The airline major said the aircraft landed safely back at Portland International Airport with 171 guests and 6 crew members.

"We are investigating what happened and will share more as it becomes available," Alaska Airlines posted on X.

Alaska Airlines CEO Ben Minicucci said: "Following tonight’s event on Flight 1282, we have decided to take the precautionary step of temporarily grounding our fleet of 65 Boeing 737-9 aircraft."

Ben Minicucci said each aircraft will be returned to service only after completion of full maintenance and safety inspections.

"We anticipate all inspections will be completed in the next few days," he said.

He said: "We are working with Boeing and regulators to understand what occurred tonight, and will share updates as more information is available. The NTSB is investigating this event and we will fully support their investigation." 

He praised the crew for handling the situation.

According to reports, the flight reached a maximum altitude of 16,325 feet before it was diverted safely to the airport.