United Airlines flight UA328, carrying 231 passengers and 10 crew on board, returns to Denver International Airport with its starboard engine on fire after it called a Mayday alert, over Denver, Colorado, U.S. February 20, 2021. A United Airlines flight landed safely at Denver International Airport on Saturday after its right engine failed, the Federal Aviation Administration said, with dramatic images showing debris from the plane scattered on the ground. Hayden Smith/@speedbird5280/Handout via REUTERS.

United Airlines flight UA328, carrying 231 passengers and 10 crew on board, returns to Denver International Airport with its starboard engine on fire after it called a Mayday alert, over Denver, Colorado, U.S. February 20, 2021. Images posted by police in Broomfield, Colorado showed significant plane debris on the ground, including an engine cowling scattered outside a home and what appeared to be other parts in a field. Hayden Smith/@speedbird5280/Handout via REUTERS.

United Airlines flight UA328, carrying 231 passengers and 10 crew on board, returns to Denver International Airport with its starboard engine on fire after it called a Mayday alert, over Denver, Colorado, U.S. February 20, 2021. The FAA said it and the National Transportation Safety Board (NTSB) will investigate. The NTSB said it had opened an investigation. Hayden Smith/@speedbird5280/Handout via REUTERS.

United Airlines flight UA328, carrying 231 passengers and 10 crew on board, returns to Denver International Airport with its starboard engine on fire after it called a Mayday alert, over Denver, Colorado, U.S. February 20, 2021. Hayden Smith/@speedbird5280/Handout via REUTERS.

United Airlines flight UA328, carrying 231 passengers and 10 crew on board, returns to Denver International Airport with its starboard engine on fire after it called a Mayday alert, over Denver, Colorado, U.S. February 20, 2021. Hayden Smith/@speedbird5280/Handout via REUTERS.