Watt's fiancee, Tilly Powell, wrote that her heart was "shattered" over the accident.
Vin Diesel's stunt double Joe Watts is fighting for his life after falling 30 feet onto his head while filming "Fast and Furious 9."
According to Mail Online, the stuntman has been placed in a medically-induced coma after a safety cable reportedly snapped while Watts jumped off a balcony on the film's set at Warner Bros Studios in Leavesden, Hertfordshire Monday.
Sources told the publication Diesel was said to have been "choking back tears" after watching Watts hit his head while performing the stunt. Production was halted following the tragic incident.
"We had an injury on the set of 'Fast 9' today in Leavesden with one of our stuntmen," a Universal spokesman told USA TODAY. "We have halted production for the day to focus on this situation." Local police also confirmed the incident, telling The Sun, "Police were called shortly before noon today following an incident at Warner Bros. Studios in Leavesden, Hertfordshire. It was reported that a man had been injured while working at the location and sustained serious injuries. The air ambulance attended and police officers are currently on scene to assist and carry out initial enquiries."
Watts' fiancee Tilly Powell took to social media to update her friends and family on Watts' condition, writing in a since-deleted Facebook post that he was "stable and being monitored closely throughout the night" and in an induced coma following the serious head injury.
Powell, who is also a stunt performer and was filming "The Hitman's Wife's Bodyguard" in London, wrote that her heart was "shattered" over the accident.
"I love him so much," she added. "He has all his family and friends by his side to get him through this!"