Two workers at the inaugural Chattanooga Motorcar festival were struck by a car on Friday morning. Jeff Banker, 59, was critically injured. Byron Evans, 53, had minor injuries and was treated and released.
Mr. Banker was upgraded to stable Saturday morning.
The driver of a 1983 Lola was Dennis Olthoff, 30.
Police said both were rushed to the hospital by ambulance after the incident at 9:34 a.m.
It happened behind the Tennessee Aquarium at Broad Street and Riverfront Parkway.
The car struck a barrier that had been placed for the event.
It happened during time trials on a 1.5-mile circuit at the riverfront.
Police said, "Time trials were being conducted along Riverside Drive when a participant, Dennis Olthoff, was negotiating serpentine barriers when the vehicle he was driving struck a traffic barrier.
"The barrier became airborne and struck two volunteers who were working the event.
"Hamilton County EMS responded and transported both volunteers to a local hospital.
"The investigation will continue in a logical manner."
Event officials said, "Two course workers were injured this morning on the time trial track after a car experienced a mechanical failure that resulted in contact with a barrier. Our number one priority is ensuring those injured get the medical attention they need, and a member of our staff is at the hospital monitoring the situation.
"We are deeply saddened by this incident. It is common practice after any incident to do a safety sweep of the course, which could take several hours, and we are working closely with investigators to determine the exact cause. While the time trial course will be shut down until further notice, other festival events will continue as planned. We remain committed to doing everything necessary to ensure the safety of everyone involved in this event and will share more details as we have them."