A passenger plane lost a section of its fuselage in mid-air, forcing it to make an emergency landing in the US state of Oregon on Friday.
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.
Alaska said 177 passengers and crew were on board and it “landed safely”.
The airline said it would “temporarily” ground all 65 of its 737 Max 9 aircraft to conduct inspections.
Boeing said it was aware of the incident and is “working to gather more information”.
The UK Civil Aviation Authority told the BBC it is “monitoring the situation very closely”.
Passenger Diego Murillo told KPTV the gap was “as wide as a refrigerator” and described hearing a “really loud bang” as the oxygen masks dropped from above.
He added: “They said there was a kid in that row whose shirt was sucked off him and out of the plane and his mother was holding onto him to make sure he didn’t go with it.”
Announcing the grounding of the 65 planes, Alaska Airlines’ CEO Ben Minicucci said: “Each aircraft will be returned to service only after completion of full maintenance and safety inspections.”
Mr Minicucci praised the efforts of the six crew members on board the flight which had reached 16,000ft (4,876m) when it began its emergency descent, according to flight tracking data.
Images sent to news outlets show the night sky visible through the gap in the aircraft’s fuselage, with insulation material and other debris also seen.
Other pictures show the seat closest to the affected section, a window seat that passengers said was unoccupied, leaning forward without its cushion.
“My heart goes out to those who were on this flight – I am so sorry for what you experienced,” Mr Minicucci said.
“I am so grateful for the response of our pilots and flight attendants.”
In an audio clip, the pilot can be heard talking to air traffic control requesting a diversion.
“We’d like to get lower if possible,” she asked. “We are an emergency. We are depressurised, we do need to return back. We have 177 passengers.”