After one of its engines blew apart, a Boeing 777 flown by United Airlines had to make an emergency landing in Denver on the weekend.
In residential areas, the blast resulted in large chunks of wreckage crashing down.
Passengers caught a video of the crippled engine, wobbling and still on fire, as minutes after the plane bound for Hawaii took off, the pilots made a secure return to the airport.
The explosion investigation is now concentrating on broken fan blades, a trend close to what followed a fatal malfunction on another plane in 2018.
So far, this is what we know.