Transcript for How larger-than-life movie stunts can turn deadly in an instant
When you're watching a movie fight scene or a car chase or a helicopter explosion, it's easy to forget that there are real people performing those stunts and sometimes they're taking real risks. Tonight we're going to explore the dangers involved in shooting these increasingly intense Hollywood action sequences. After a week of stunts gone wrong. Here's ABC's gio Benitez. Reporter: From the high-speed chases of "Mad max: Fury road," to the heart-pounding hand-to-hand combat in "Captain America: Civil war." Stunt performers work behind the scenes to make seemingly impossible feats into big-screen action sequences. But these larger-than-life stunts can turn deadly in an instant. Lost control, went across the street over a curb and through a glass pane window into a building across the street. That audio obtained by TMZ describes the fatal'll crash that took place earlier this week after stuntwoman joy Harris lost control of her motorcycle. The stunt actor was airborne through the building. Reporter: She was pronounced dead on the set in Vancouver. She had reportedly performed the stunt successfully four times before something went wrong on the fifth take. Harris, seen here in video from a 2015 competition, was the first female African-American professional road racer. Her part in the sequel to the record-breaking 2016 hit "Deadpool" was her first major movie role. The film's star Ryan Reynolds paid tribute to the stuntwoman on Twitter saying, "We're heartbroken, shocked, and devastated but recognize nothing can come close to the grief and inexplicable pain her family and loved ones must feel in this moment." And this isn't the first on-set tragedy to rock Hollywood this summer. In July stuntman John bernaker was killed on the set of AMC's hit series "The walking dead." TMZ also obtaining audio from that phone call. We had someone fall about 25 feet off of a balcony straight onto concrete. We need an ambulance asap. Reporter: Bernaker reportedly bleeding and barely conscious after plunging to the ground. Is he able to talk to anybody? No. Reporter: He was transported to a level 1 trauma center but later died of his injuries. A seasoned veteran, he worked on "The hunger games" and in marvel's upcoming action movie "Black panther." Stewart Wilson has worked in the industry for more than 2 1/2 decades. Some of his most prominent roles have come as Bruce Willis's stunt double in hits like "Live free or die hard." I've been with Bruce Willis, doubling him. We just got back from doing our 21st film together over the past 11 years. I think we have a really good working relationship. We have such rapport now that I know what he expects me to do. I know how he'll move. Spine pad. Reporter: Through his career Wilson has racked up plenty of bumps and bruises. Torn left quad, blown out right knee, compression injury on c-5, 6 and 7, 1/3 less sensory feeling in my right arm. And in March I don't know if you can see this lump in my shoulder, I tore all the ligaments in my shoulder going out a window onto the sidewalk in New York of all places. Reporter: But he says he doesn't regret his career choice. There is that adrenaline rush. And when an entire cast and crew is watching and you've got to hit your mark and you have to have it done correctly, if you have to pull that off it is a big rush when you do that. For 30 seconds everybody loves you. Then you, you know, walk off to craft service and nobody cares anymore. So till the next one. Reporter: Wilson teaches combat acting classes at a school in L.A. His sage safety advice for new students? If something doesn't look right, speak up. Reporter: It's not only stunt performers who take risks. Many a-listers take pride in performing their own stunts, like mission: Impossible" star Tom Cruise, who was injured on the set of the franchise's sixth installment this week. Attempting to jump from one building to another, seen limping afterwards in this video. On the set of "Star wars: The force awakens" Harrison Ford broke a leg after being crushed by a door. Stunts by their very definition carry risk, and risk is not something we eliminate. Risk is something we manage and and we control. Reporter: Chris palmer has built a career out of trying to make high-flying, high risk stunts safer. The short version and I say it jokingly sometimes is I'm the adult supervision. My job is to try to identify the risks that are face the production. Reporter: His resume includes work on more than 700 projects, including the James bond series and "Olympus has fallen." And after the tragic helicopter accident that killed actor vic morrow and two children on the set of "Twilight zone," palmer worked to rework safety standards in Hollywood. I think that what we've seen with each, you know, high-profile accident in this injury, there is a lot of discussion in the industry, well, we're going to change things. However, the commitment and the actual follow-through isn't always there. What is there, he says, is pressure to perform with bigger, better feats. People expect to be wowed. It's also being driven by the distributors that if you're asking me to put up this kind of money for the rights to a film it's got to be something that's got a really good chance to be successful. And big action still sells. Reporter: Members of the crew not immune either. In 2015, 27-year-old Sarah Jones was killed while filming "Midnight rider" on an active train trestle. At first it was like a quiet. Like people were in shock. I remember hearing somebody say oh, my gosh, she's dead. Reporter: Joyce Gillard was on set that day. They wanted to get the shot. So whatever it took to get the shot is what they did. The entire crew was put in a situation where we didn't know what to do and we all had to basically run for our lives. Reporter: The director of the film and two others eventually pled guilty to involuntary manslaughter and criminal trespassing. I used to tell people, you know, when I'd get called in to investigate accidents, no one got up that morning thinking I'm going to be in intensive care or I'm going to be in the morgue tonight. And I think sometimes in the industry we develop sort of a sense of invulnerability. We do amazing things every day. Difficult things in difficult places under very difficult circumstances. And we do them very well and we do them very safely. But I think that everyone has to sometimes stop and think, well, what if. Reporter: Now the shards of glass and caution tape where joy Harris was killed a grim reminder that what if can turn into a tragic reality in a heartbeat. For "Nightline" I'm gio Benitez in New York.
This transcript has been automatically generated and may not be 100% accurate.