Plane debris falls from sky onto Colo. neighborhood during emergency landing

DENVER - A United Airlines plane made a safe emergency landing at Denver International Airport after dropping debris on a neighborhood Saturday.

The Federal Aviation Administration said in a statement that the Boeing 777-200 returned to the airport after experiencing a right-engine failure shortly after takeoff. Flight 328 was flying from Denver to Honolulu when the incident occurred, the agency said.

United said in a separate statement 231 passengers and 10 crew members were on board. The airline released no further details. No injuries have been reported. 

On the ground, photos posted by the Broomfield Police Department showed large, circular pieces of debris leaning against a house in the suburb. 

Broomfield police said they began getting several calls Saturday afternoon from people saying they had heard a loud explosion and were seeing smoke in the sky.

Aviation safety experts said the plane appeared to have experienced an uncontained and catastrophic engine failure. Such an event is extremely rare and happens when huge spinning discs inside the engine suffer some sort of failure and breach the armored casing around the engine that is designed to contain the damage, said John Cox, an aviation safety expert and retired airline pilot who runs an aviation safety consulting firm called Safety Operating Systems.

"That unbalanced disk has a lot of force in it and it’s spinning at several thousand rotations per minute ... and when you have that much centrifugal force, it has to go somewhere," he said in a phone interview with the Associated Press.

Pilots practice how to deal with such an event frequently and would have immediately shut off anything flammable in the engine, including fuel and hydraulic fluid using a single switch, Cox said.

Despite the scary appearance of a flaming engine, most such incidents don't result in loss of life, Cox added.

Meanwhile, police have taped off the locations where the debris landed and are asking those in the area not to touch or move it.

One large apparent piece of the plane landed in someone's front yard, just appearing to narrowly miss landing on the roof. 

Broomfield Police Department spokesperson Rachel Wechte said their department will begin questioning witnesses for the investigation but will eventually turn things over to the National Transportation Safety Board.

"I’m honestly shocked (that nobody was hurt), looking at this debris field and how busy Commons Park is, this is a very popular spot in Broomfield," Wechte said.

She said the park includes a dog run, turfs and a playground. She credits the cold weather for the reason not many were at the park when the debris fell.

"The fact that we are still not getting reports of any injuries is absolutely shocking at this point. It’s amazing," she said.

Tyler Thal, who lives in the area, told The Associated Press that he was out for a walk with his family when he noticed a large commercial plane flying unusually low and took out his phone to film it.

"While I was looking at it, I saw an explosion and then the cloud of smoke and some debris falling from it. It was just like a speck in the sky and as I’m watching that, I’m telling my family what I just saw and then we heard the explosion," he said in a phone interview. "The plane just kind of continued on and we didn’t see it after that."

No other details were immediately available from authorities.

The Associated Press contributed to this report. This story was reported from Los Angeles.