A Boeing 737-800 plane made an emergency stop on Sunday after the crew reported the engine cowling fell off and struck the wing flap during takeoff from Denver International Airport in U.S. state of Colorado, authorities said.

Southwest Airlines Flight 3695 returned safely to Denver International Airport around 8:15 a.m. local time (1515 GMT) on Sunday after the incident, said the U.S. Federal Aviation Administration (FAA) in a statement.

The plane was headed to William P. Hobby Airport in Houston, said the FAA, noting that the agency will investigate the incident.

Southwest Airlines said in a statement that the flight landed safely after experiencing a mechanical issue.

"Our customers arrived at Houston Hobby on another aircraft, approximately three hours behind schedule," said the airline, adding that Southwest's maintenance teams are reviewing the aircraft.

The plane was delivered in 2015, and the aircraft manufacturer CFM made the engine, according to FAA records. The engine cowling is a removable metal covering on the engine.

A passenger on the flight posted a video of debris flying off of the plane as it was moving down a runway at Denver International Airport, reported local KUSA television station.

A picture posted after the plane's safe landing shows sizable pieces missing from the plane's right engine, the report added.

From air traffic control recordings from LiveATC.net, a Southwest pilot told a Denver International Airport air traffic controller, "We don't actually see it from the cockpit, that's just what the crew in back is telling us. Our engines seem to be fine, but we are structurally damaged," according to the report.

Boeing has grappled with significant quality and safety issues concerning its aircraft for years, leading to the prolonged grounding of specific models and halted deliveries.

From October 2018 to March 2024, the company faced several incidents that underscored concerns about the safety and reliability of its aircraft.