WRITETHRU, 4:50 PM: A rookie stuntwoman who was killed in a motorcycle crash on the Vancouver set of Deadpool 2 has been identified as the first African-American female professional road racer. Joi “SJ” Harris was doing her first film as a stunt performer, Deadline has learned. A spokesman for ACTRA confirmed her identity to Deadline, though she is not a member of the Canadian actors union.

Joi Harris via Facebook

Production on the superhero sequel was shut down immediately after the fatality, and there’s no word on when filming will resume. It’s the second on-set death in North America in a month; John Bernecker suffered massive head injuries in a fall July 12 on the set of The Walking Dead and died shortly afterward.

Details still are coming in, but witnesses said the crew was filming a stunt sequence when Harris lost control of her motorcycle and crashed through a plate-glass window at Shaw Tower on West Waterfront Road near Jack Poole Plaza. The stuntwoman was playing the Domino character in the sequence in the Ryan Reynolds superhero sequel. Actress Zazie Beetz is playing Domino in Deadpool 2. Reynolds tweeted a photo of Beetz in character two weeks ago.

A source close to the situation said Harris, who was an experienced road racer, had been rehearsing the stunt all day Saturday. A studio production source said that there were “two full days of rehearsals over the weekend, and on Monday, they ran the stunt five-plus times before filming.”

An eyewitness told Deadline that, on the last take, the bike seemed to accelerate when it was supposed to slow as she took the corner. Harris was not wearing a helmet when the accident occurred today because the Domino character did not wear one in the scene.

Deadline has been told that the crew is enduring very long hours — that includes weekends — and that workers feel like they are being run ragged. “People are exhausted by the schedule,” one crew member told Deadline, noting that they were working multiple 16-hour days in a row. That, however, is disputed by a studio production source, who said the daily shooting schedule on the Vancouver set is 12-13 hours, and there were only two 15-plus-hour days, about three weeks ago.

Reynolds said he was “devastated” by Harris’ death. Producer Simon Kinberg had no comment when contacted by Deadline.

David Leitch, director of Deadpool 2 said in a statement to Deadline: “I’m deeply saddened by the loss of one of our stunt performers today. No words can express how I and the rest of the Deadpool 2 crew feel about this tragedy. Our thoughts are with her family, friends and loved ones in this difficult time.” A 20th Century Fox spokesman told Deadline: “We are deeply saddened by the accident that occurred on the set of Deadpool 2 this morning. Our hearts and prayers are with the family, friends and colleagues of our crew member during this difficult time.”

Joi Harris via Facebook

According to her online bio, Harris began motorcycle riding in Brooklyn and in 2013 — after logging more than 1,500 training hours — became the first African American woman licensed to actively compete in American Motorcyclist Association races. An injury from an on-track crash while training for her first race forced Harris to wait until 2014 to begin competing in the American Sportbike Racing Association/Championship Cup Series. Since then she had been an outspoken advocate for female racing.

“I’ve learned to accept that I am not the greatest rider that exists and that there is always something to learn when on track and pushing limits,” she said on her website. “Sometimes I’m going to eat it if I’m impatient. Everything takes time. Face your fears — you never know what you can be missing out on.”

The Vancouver Police Department confirmed the death on social media this morning. Law enforcement in Reynolds’ hometown said they are investigating the incident along with the BC Coroner’s Service and WorkSafeBC, British Columbia’s version of the U.S.’ Occupational Safety and Health Administration.

“We have five officers on site and two are looking at immediate occupational safety and health issues to make sure the site is safe,” Trish Knight Chernecki, senior manager for WorkSafeBC, told Deadline. “The other three officers on site are investigating the cause of the incident and the prevention of future incidents.”

Andy Watson, a spokesman for the BC Coroner’s Service, told Deadline: “We have opened an investigation,” said its spokesman, “Anytime there is a fatality in the province we investigate. We have a mandate to prevent future deaths and to make any recommendations that could come from our findings.”

A CTV reporter tweeted this from the site:

Vancouver Mayor Gregor Robertson said the city will continue to support the filming there when the crew recovers from the emotional trauma. “We are extremely saddened to hear of the tragic incident that took the life of a stuntwoman working on the set of Deadpool 2 downtown earlier today,” he said in a statement. “Our condolences go out to her family and friends, and to all those working on set who have been impacted by the loss of their colleague. We will continue to support the crew and production as they work to recover emotionally and as they continue their next phase of filming.”

As previously mentioned, today’s accident marks the second stunt-related on-set death in North America in about a month; stuntman John Bernecker suffered massive head injuries in a fall July 12 on the set of The Walking Dead and later died at Atlanta Medical Center. That was believed to be the first stunt-related death in the United States in more than 17 years.

The veteran stuntman was doing a fight scene for the zombie apocalypse drama with actor Austin Amelio on a balcony when he fell about 30 feet to a concrete floor, just missing the safety pad and landing on his head and neck.

The Occupational Safety and Health Administration and SAG-AFTRA opened investigations into Bernecker’s death. Mike D’Aquino, a spokesman for the regional OSHA office in Atlanta, said that the investigation could take up to six months to complete. The Coweta County Coroner’s Office and Sheriff’s Department have ruled the death an accident and closed their respective cases into the matter.

AMC temporarily halted production on Season 8 of the zombie apocalypse series in the wake of the accident.

Erik Pedersen contributed to this report.