In a video filmed from inside the ship, in which 231 passengers and 10 crew members were traveling, the right engine is seen in flames on the wing of the Boeing 777-200, while the plane flew over an arid landscape.  "At one point I thought we were going to die because we began to lose height just after the explosion" passenger David Delucia told The Denver Post, the AFP agency reported.
Among the images published in social networks there is a photo of a large circular piece of the United Airlines plane in a courtyard in Broomfield, a suburb of Denver, in the state of Colorado.
"Flight UA328 from Denver to Honolulu registered an engine failure shortly after takeoff, returned safely to Denver and was greeted by emergency crews as a precaution" United Airlines said in a statement.
Most of the passengers flew to Honolulu on another flight, while others who did not want to travel to Hawaii were accommodated in a hotel.
In a recording of the distress call obtained from the LiveATC website, which broadcasts air traffic communications, the pilot requested emergency permission to return to Denver.
"We have registered engine failures, we need to go back. Mayday, mayday" said the pilot.
Meanwhile, residents of the suburb of Broomfield found large pieces of the plane scattered throughout their community, including a giant circular piece of metal that landed in a courtyard
"It landed in the top of my truck "said a neighbor, reporting that another large piece had made a 1.5 meter diameter hole in the roof of another house.
The Denver Post newspaper published photos taken from tie It shows smoke on the right wing of the plane and reported that crowds came to Broomfield to observe and photograph the fragments scattered in the city.
The Federal Aviation Administration (FAA) said that he was "aware of reports of fragments in the vicinity of the plane's flight path", adding that the agency and the National Transportation Safety Board are investigating the incident.
"If you find fragments, PLEASE do not touch or move them. @NTSB wants all fragments to remain in place for investigation, "Bloomfield police tweeted.