Runners from around the country showed up for the Rock/Creek StumpJump race Saturday on Signal Mountain and Walden's Ridge.
But race officials said that this year, one runner died during the StumpJump.
Mark McKnight, a representative from Rock/Creek, said a runner collapsed on the trail around 4 p.m., about 20 miles into the 32-mile race. A doctor was running just behind him, and he and several other runners stopped to try and assist the man. McKnight said there was nothing they could do.
"They're thinking it was some kind of aneurysm or heart failure of some sort," he said, adding there was no confirmation from a hospital or coroner about the cause of death.
McKnight said this has never happened before at the StumpJump race.
"In terms of just falling down on the trail like this, we've never had anyone die on us," he said. "It was a pretty shocking thing for us."
The man's identity had not been released as of Saturday night.