BROOMFIELD, Colo. (AP) — Federal regulators are investigating what caused a catastrophic engine failure on a United Airlines plane that rained debris on Denver suburbs as the aircraft made an emergency landing.

Authorities said nobody aboard or on the ground was hurt despite large pieces of the engine casing that narrowly missed homes below.

The Federal Aviation Administration said in a statement that the Boeing 777-200 returned to the Denver International Airport after experiencing a right-engine failure shortly after takeoff.

Flight 328 was flying from Denver to Honolulu when the incident occurred.

United says there were 231 passengers and 10 crew on board.

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