A jet crashed at a Tennessee air show shortly after taking off Saturday, officials and witnesses said.
"He was only in the air after takeoff for less than two minutes before he crashed," a witness, Jennifer Culver, told NBC News.
She saw the Aero L-39 go down and out of sight behind a metal hangar, where it crashed in the 4:30 p.m. accident.
"I looked over and I saw him, he was going kind of in a nose dive," Bruce Dunlap told NBC station WBIR in Knoxville.
"At first I didn't think anything about it because I figured he would pull up and come on, then a few seconds later we saw a puff of smoke, then the rescue squad and helicopters started going that direction," he said.
The pilot was the only person aboard and was not identified. His condition was unclear.
The Wings Over Big South Fork Air and Car Show at Scott County Municipal Airport in Oneida was cancelled, airport manager Hank Duvall said.
The National Transportation Safety Board said it was investigating the cause of the crash. Oneida is about 60 miles northwest of Knoxville.