A World War II-era plane crashed into a box-seat area near a grandstand at the National Championship Air Races in Reno, Nev., sending debris flying and causing what race officials called “a mass casualty situation.”

At least three people died, including Jimmy Leeward, 74, the pilot of the crashed plane, and more than 50 injured people were taken to local hospitals, according to officials.

Video of the crash at approximately 4:20 p.m. local time showed the plane, known as the Galloping Ghost, a P-51 Mustang, suddenly lurching upward into the air and then dropping down on the crowd.

“You could see that he tried to pull back under and try and miss as many people as possible,” said Carly Holmes, who was watching the race from bleacher seats, according to ABC News Radio. “He missed the bleachers but he hit the crowd.

“You see everyone stand up,” Holmes said. “And you didn’t know which direction to go because you didn’t know where the plane was going. We just saw the plane hit.”

The AP cited video that showed bodies and wreckage at the front of the stands. Witnesses described survivors with missing body parts and other extreme injuries.

Fifty-four injured people were taken to local hospitals, Reno Air Races president Mike Houghton told reporters. He did not have a count on the number killed.

“The NTSB is taking over the site, the investigation and the release of specific numbers in different categories,” Houghton said.

Some National Transportation Safety Board staff members already were on the site, and the entire team was expected to launch at 2 a.m. Saturday.

Prior to Houghton’s statement, Stephanie Kruse, a spokeswoman for the Regional Emergency Medical Service Authority, told The Associated Press that 56 people had been taken to three local hospitals –15 in critical condition, 13 in serious condition with potentially life-threatening injuries and 28 in non-serious or non-life threatening condition.

Renown Regional Medical Center in Reno went into “code triage” after the accident and was told to expect 80 to 1oo people, ABC News affiliate KOLO in Reno reported, but the hospital later told KOLO its main hospital and a satellite facility admitted 29 people.

Of the 25 people admitted to Renown’s main facility, 12 were in critical condition, 11 were in fair condition and two had died as of 7:30 p.m. local time, an official told ABC News.

Some victims went to other hospitals, including at least 25 to St. Mary’s Hospital in Reno, an official there said. Conditions were not available for those patients, who generally were less seriously injured than those at Renown.

Multiple Federal Aviation Administration inspectors were observing the air race when the plane crashed, leaving a wide debris field, according to Ian Gregor of the FAA.

“Pieces everywhere,” said Holmes, who witnessed the crash. “You hear everybody just in horrible pain, screaming, running. … It was horrific to watch.” 

Connie Camit had just left the grandstand for a refreshment stand with two of her children, 14 and 5, according to ABC News Radio.

“Just as we were standing there, we heard this big crash, turned around and I seen airplane pieces, parts flying everywhere,” she said. “We just heard everybody screaming, sirens. It was just chaos, complete chaos.”

Nevada Gov. Brian Sandoval asked people to donate blood to aid crash victims, and hailed emergency crews and civilians who aided victims at the scene.

“I’m told there were over 100 spectators that had medical training that came out to assist the victims,” Sandoval said. “And I think that speaks very well of our community.”

The remainder of the National Championship Air Races were canceled, race officials said, citing the death of Leeward, a real estate developer from Ocala, Fla., and other casualties.

“Concerned family members should call 775.972.6663 and Air Race staff is working to locate and establish the status of all involved,” race officials said in a written statement.

Houghton later added, “We are all devastated by this tragedy, and we are doing everything we can to move along and communicate and work with the folks that are directly and adversely affected by this.”

He described Leeward as “a very experienced and talented and qualified pilot” whose “medical records and everything are up-to-date, spot-on.”

ABC News’ Matt Hosford and Jacob Beckman contributed to this report.