It's a small miracle nobody was hurt or killed in Colorado over the weekend after an engine blew on a United jet and rained huge pieces of debris on neighborhoods near the Denver International Airport. In fact, one of the engine's fan blades came down on a soccer field in Bloomfield. As the investigation unfolds, here is the latest:
- Metal fatigue: The investigation could take more than a year, but an early report by the NTSB suggests that "metal fatigue" caused one of the engine fan blades to break, reports CNN. The blade then apparently sheared off a second one, and the engine caught fire. "My daughter was sitting on the window and ... I was just like, 'Don't look, like ... let's close it up and let's just pray,'" passenger Brenda Dohn recalls. The engine on the Boeing 777 is made by Pratt & Whitney, part of its PW4000 series.
- Other incidents: That same day, a Boeing 747 in the Netherlands with similar engines—from the PW4000 series, though a different model—suffered a similar fate, reports Reuters. In December, a Japan Airlines jet with engines from the PW4000 series also had to return to the airport because two fan blades broke on one of them. And three years ago, a fan blade broke on a United jet with a PW4000 series engine out of San Francisco, per NBC News. As in Colorado, all the flights landed safely.