A video posted on social media shows the interior of the plane moments after a window was lost mid-flight.
Passengers on the Alaska Airlines plane, which was carrying 177 people, could be seen using emergency oxygen masks but remained remarkably calm.
The plane was forced to make an emergency landing in the US state of Oregon, and the US Federal Aviation Administration said that the plane “returned safely… after the crew reported a pressure problem.”
Alaska Airlines has now grounded 65 Boeing 737-9 aircraft. The company said that the planes will not return to service until complete maintenance and safety checks are carried out.
