US-based Alaska Airlines grounded all its Boeing 737 MAX 9 planes on Friday after a flight with 177 people onboard made an emergency landing in the state of Oregon, with passengers saying a window panel blew out after takeoff. Flight 1282 departed from Portland International Airport Friday evening before returning safely around 20 minutes later after cabin crew reported a “pressurization issue,” according to the Federal Aviation Administration. Images posted on social media showed the window panel of a plane blown out, with emergency oxygen masks hanging from the ceiling. “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,” Alaska Airlines CEO Ben Minicucci said in a statement. “Each aircraft will be returned to service only after completion of full maintenance and safety inspections,” he said, anticipating checks would be finished in a few days. Kyle Rinker, a passenger on the flight, told CNN that a window popped off soon after takeoff. “It was really abrupt. Just got to altitude, and the window/wall just popped off and didn’t notice it until the oxygen masks came off,” he told the broadcaster. Another passenger, Vi Nguyen, told The New York Times that a loud noise during the flight had woken her. “I open up my eyes and the first thing I see is the oxygen mask right in front of me,” Nguyen told the newspaper. “And I look to the left and the wall on the side of the plane is gone.” “The first thing I thought was, ‘I’m going to die,'” she added. – ‘Rare occurrence’ – The National Transportation Safety Board, FAA and Alaska Airlines each said they were investigating the incident. “The aircraft landed safely back at Portland International Airport with 171 guests and 6 crew members,” the airline said in an earlier statement. “While this type of occurrence is rare, our flight crew was trained and prepared to safely manage the situation,” it added. The Boeing 737 Max 9 plane took off at 5:07 pm, heading to Ontario, California, before returning to the Portland airport, according to the flight tracking website FlightAware. The plane was certified airworthy in October and was newly delivered to Alaska Airlines, according to the FAA registry website. Boeing wrote on X that it was gathering more information and a technical team stood ready to support the investigation. In his statement, Minicucci said Alaska Airlines was “working with Boeing and regulators to understand what occurred.” Boeing has struggled in recent years with technical and quality control issues related to its 737 MAX models. In December, the US aviation giant told airlines that MAX aircraft should be inspected to check for loose hardware on plane rudder control systems after an international operator discovered a bolt with a missing nut while performing routine maintenance. Boeing’s 737 MAX planes were grounded worldwide following two MAX 8 crashes in 2018 and 2019 that killed 346 people in total. The FAA only approved the planes’ resuming of service after the company made changes to its flight control system.