The Federal Aviation Administration (FAA) has ordered the “temporary grounding” of 171 Boeing 737 Max 9 airplanes this morning after section of fuselage separated off the side of an Alaska Airlines flight on Friday, leaving a gaping hole in the side of the plane. The agency said in its announcement that it will send an Emergency Airworthiness Directive out soon to require an inspection of all of the grounded planes that “will take around four to eight hours per aircraft.”

The New York Times reported yesterday that flight 1282 from Portland International Airport had made an emergency landing back at the same airport just 20 minutes later because of a “pressurization issue” that resulted in a wall of the plane blowing out. Incredibly, there were only minor injuries reported. According to the Times, no one was in the seat immediately next to the wall when it disappeared, and only minor injuries were reported. The abrupt depressurization also reportedly yanked the shirt off of a teenage passenger sitting nearby.

Prior to the FAA’s decision, Alaska Airlines grounded its own fleet of 65 Boeing 737 Max 9 planes for inspection. This morning, the company said it had inspected over a quarter of its fleet, with “no concerning findings.”

Most recently, on December 28th, the FAA announced it was monitoring inspections of 737 Max planes after loose bolts were discovered in the rudder-control systems of two planes.