A small plane crashed at Aspen/Pitkin County Airport in Colorado on Sunday, the Pitkin County Sheriff's office said.
Further details, including how many people had been on board the plane and their condition, were not immediately available, the office said.
The comedian Kevin Nealon described seeing the crash on his Twitter account.
"Horrible plane crash here at Aspen airport," he wrote in one of several messages sent from the scene. "Exploded into flames as it was landing. I think it was a private jet."
LeAnn Rimes, the country singer, also took to Twitter to describe seeing what she also described as the "horrible" crash. "So sad!" she wrote.
Located in the Rocky Mountains about 190 miles west of Denver, Aspen is known for its ski resorts.
The airport has been closed due to the crash, which occurred at 12:30 MT (1930 GMT), the Federal Aviation Administration said on its website.