EXCLUSIVE: The federal Occupational Safety and Health Administration is investigating Monday’s accident on the Atlanta set of CBS’ MacGyver that left stunt coordinator Justin Sundquist in a medically induced coma. “OSHA has opened an investigation,” Eric Lucero, a spokesman for the U.S. Department of Labor, told Deadline.

CBS

Sources say that Sundquist is showing some signs of improvement but remains unconscious. He was injured in a stunt that called for him to fall off the back of a tractor trailer and hit the ground rolling. But he hit his head on the ground and was rushed to a nearby hospital with a serious head injury.

Sundquist had been hired as the show’s stunt coordinator only recently, replacing Jeff Wolfe, who’d been the MacGyver stunt coordinator since the first episode. The rebooted show currently is filming its third season.

CBS TV Studios told Deadline on Tuesday, “The production team is cooperating with the authorities investigating the accident, and our primary concern at this time is Justin’s health and well-being.”

CBS had no comment.