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 people to donate.
Among the dead was Leeward, of Ocala, Fla., a veteran airman and movie stunt pilot who named his P-51 Mustang fighter plane the "Galloping Ghost," according to Mike Houghton, president and CEO of Reno Air Races. Officials earlier said Leeward was 80.
Leeward, the owner of the Leeward Air Ranch Racing Team, was a well-known racing pilot. His website says he has flown more than 120 races and served as a stunt pilot for numerous movies, including "Amelia" and "Cloud Dancer."
In an interview with the Ocala (Fla.) Star-Banner last year, he described how he has flown 250 types of planes and has a particular fondness for the P-51, which came into the war relatively late and was used as a long-range bomber escort over Europe. Among the famous pilots of the hot new fighter was WWII double ace Chuck Yeager.
"They're more fun. More speed, more challenge. Speed, speed and more speed," Leeward said.
Leeward talked about racing strategy in an interview Thursday with LiveAirShow TV while standing in front of his plane.
"Right now I think we've calculated out, we're as fast as anybody in the field, or maybe even a little faster," he said. "But uh, to start with, we didn't really want to show our hand until about Saturday or Sunday. We've been playing poker since last Monday. And uh so, it's ready, we're ready to show a couple more cards, so we'll see on Friday what happens, and on Saturday we'll probably go ahead and play our third ace, and on Sunday we'll do our fourth ace."
Houghton described Leeward as a good friend.
"Everybody knows him. It's a tight-knit family. He's been here for a long, long time," Houghton said.
He also said Leeward was a "very qualified, very experienced pilot" who was in good medical condition. He suggested Leeward would have made every effort to avoid casualties on the ground if he knew he was going to crash.
"If it was in Jimmy's power, he would have done everything he possibly could," Houghton said.
The National Championship Air Races draws thousands of people to Reno every September to watch various military and civilian planes race.
The FAA and air race organizers spend months preparing for air races as they develop a plan involving pilot qualification, training and testing along with a layout for the course. The FAA inspects pilots' practice runs and brief pilots on the route maneuvers and emergency procedures.
Sen. Harry Reid, Rep. Mark Amodei and other officials issued statements Friday saying they were shocked and saddened by the crash.
"My thoughts are with the families of those who have lost their lives and with those who were wounded in this horrific tragedy," Reid said. "I am so grateful to our first responders for their swift action and will continue to monitor this situation as it develops."