RENO, Nev. (AP) -- As thousands watched in horror, a World War II-era fighter plane competing in a Nevada event described as a car race in the sky suddenly pitched upward, rolled and did a nose-dive toward the crowded grandstand.
The plane, flown by a 74-year-old veteran Hollywood stunt pilot, then slammed into the concrete in a section of VIP box seats and blew to pieces in front the pilot's family and a tight-knit group of friends who attend the annual event in Reno.
"It absolutely disintegrated," said Tim O'Brien of Grass Valley Calif., who attends the races every year. "I've never seen anything like that before."
Three people were killed and more than 50 injured amid a horrific scene strewn with smoking debris.
Authorities say it appears a mechanical failure with the P-51 Mustang - a class of fighter plane that can fly in excess of 500 mph - was to blame. Some credit the pilot, Jimmy Leeward, with preventing the crash from being far more deadly.
Leeward was among those killed.
"If he wouldn't have pulled up, he would have taken out the entire bleacher section," said Tim Linville, 48, of Reno, who watched the race with his two daughters.
Left in its wake were bloodied bodies spread across the area as people tended to the victims and ambulances rushed to the scene. Video of the aftermath shows a man with his leg severed at the knee.
The National Championship Air Races have been deadly before. Two pilots died at the event in 1994. And organizers softened two of the curves pilots negotiate after two more pilots crashed into nearby neighborhoods in 1998 and 1999.
In 2007 and 2008, four pilots were killed at the races, prompting local school officials to consider barring student field trips to the event.
Planes at the yearly event fly wingtip-to-wingtip as low as 50 feet off the sagebrush at speeds sometimes surpassing 500 mph. Pilots follow an oval path around pylons, with distances and speeds depending on the class of aircraft.
Mike Houghton, president and CEO of Reno Air Races, said at a news conference hours after the crash that there appeared to be a "problem with the aircraft that caused it to go out of control." He did not elaborate.
He said the rest of the races have been canceled as the National Transportation Safety Board investigates.
"The way I see it, if he did do something about this, he saved hundreds if not thousands of lives because he was able to veer that plane back toward the tarmac," said Johnny Norman, who was at the show.
O'Brien, who is chairman of an air show in his hometown in California, was photographing Friday's races when the crash occurred.
He said the P-51 Mustang was racing six other planes, and was in the process of moving from third place into second, when it pitched violently upward, rolled and then headed straight down.
From the photos he took, O'Brien said it looked like a piece of the plane's tail called a "trim tab" had fallen off. He believes that's what caused the plane's sudden climb.
When the aircraft hit the ground, there was a "big explosion but no fire," O'Brien said.
"The propeller (was) spinning very fast, and there was a lot of mass coming down all at once," he said. It was a "very violent impact."
Afterward, a number of people were standing around, and "all we could do was hug each other," he said.
Maureen Higgins of Alabama, who has been coming to the air races for 16 years, said the pilot was on his third lap when he lost control.
"Obviously he had no control. He was wobbling. He went upside down and then he headed straight for us, straight at the grandstand."
She was sitting about 30 yards away from the crash and watched in horror as the man in front of her started bleeding after debris hit him in the head.
"I saw body parts and gore like you wouldn't believe it. I'm talking an arm, a leg," Higgins said "The alive people were missing body parts. I am not kidding you. It was gore. Unbelievable gore."
Renown Regional Medical Center spokeswoman Kathy Carter confirmed that two others besides the pilot died, but did not provide their identities.
Stephanie Kruse, a spokeswoman for the Regional Emergency Medical Service Authority, told The Associated Press that emergency crews took a total of 56 injury victims to three hospitals. She said they also observed a number of people being transported by private vehicle, and those people were not included in the count.
Kruse said of the total 56, at the time of transport, 15 were considered in critical condition, 13 were serious condition with potentially life-threatening injuries and 28 were non-serious or non-life threatening.
"This is a very large incident, probably one of the largest this community has seen in decades," Kruse told The Associated Press. "The community is pulling together to try to deal with the scope of it. The hospitals have certainly geared up and staffed up to deal with it."
Gov. Brian Sandoval noted at a news conference that area hospitals were in need of blood in the wake of the crash, and he encouraged