- United said no injuries were reported on board.
- The Boeing 777-200 safely returned to Denver. Images shared on social media showed what appeared to be a part of the engine covering in front of a house, among other debris.
- There were 231 passengers and 10 crew members on board United Flight 328, United said.
The plane returned to Denver where it landed safely. Images shared on social media showed what appeared to be a part of the engine covering in front of a house, while police shared images of other debris. United said there were no injuries reported on board the flight.
"The FAA is aware of reports of debris in the vicinity of the airplane's flight path," the agency said in a statement.
The plane departed Denver International Airport shortly after 1 p.m. Mountain time and returned to the airport less than 30 minutes afterward, according to flight-tracking site Flightradar24.
The National Transportation Safety Board and the FAA said they are investigating the incident. The Broomfield Police Department in Colorado said the plane dropped debris in several neighborhoods and warned against touching or moving pieces of the plane.
There were 231 passengers and 10 crew members on board United Flight 328, a twin-engine, wide-body Boeing 777, when its right engine failed, United said.
United said it is in contact with the FAA, NTSB as well as local law enforcement about the flight.
"All passengers and crew have deplaned and been transported back to the terminal" in Denver, United said in a statement. The carrier said most passengers on the flight were rebooked and on their way to Honolulu on another flight while those who didn't want to be rebooked on Saturday were provided hotel stays.
"Extremely rare engine failures like this prove there is no substitute for experience and that the most important aircraft safety system is two well-trained, highly skilled, professional pilots at the controls on the flight deck," said the Air Line Pilots Association, the union that represents United's pilots.
The Association of Flight Attendants-CWA, which represents United's cabin crews, said its employee assistance and safety committees were providing assistance to crews.
"We're grateful the plane landed safely," the labor union said.
Boeing said it was aware of reports about the incident. Flightradar24 said the plane was powered by two Pratt and Whitney PW4000 engines. The Raytheon Technologies unit didn't immediately respond to a request for comment.