LOS ANGELES (AFP) - A vintage World War II aircraft killed at least three people and injured more than 50, some critically, when it ploughed into spectators at an air show in the US state of Nevada and there were fears Saturday that the death toll would rise. Amateur video of the accident in Reno captured the moment the P-51 Mustang fighter, called the Galloping Ghost, smashed almost vertically to the ground near a packed grandstand. At least 15 victims were in a critical condition in hospital. I did have an opportunity to visit the site, and it is horrific, Nevada Governor Brian Sandoval told reporters. Witnesses said the aircraft crashed Friday into an area of boxes - roped-off areas for spectators - while one said the pilot prevented even greater casualties by swerving to avoid hitting the grandstand itself. It pretty well wiped out the front of the box area, said Mike Houghton, the head of the Reno Air Racing Association, declining to comment on how many people could have died, while giving the number of injured as 54. We are all devastated by this tragedy, he added, briefing reporters. The aircraft was piloted by a Florida real estate developer, named as Jimmy Leeward. Amateur video of the accident, shot from the grandstand, showed people gasping in horror as the plane came down. Reno Air Racing Association Mike Draper said the plane was a lap or two into the race when its pilot called in a mayday. We dont know why it crashed. The pilot did call in. He did pull out of the lap, which is what they do. They usually pull up, directly up to clear the race track, he added. Eyewitness Ben Cissell praised the pilot. I think that that pilot in the last two seconds pulled up because he saw the bleachers and I would guess he probably saved 200 to 300 other people, he told CNN. The local Renown medical centre said earlier it was treating 23 of the injured. Another Reno hospital, the Saint Marys Regional Medical Centre, meanwhile said it had 25 patients. The National Transportation Safety Board (NTSB) launched an immediate investigation, and would give updates on the number of dead in the accident, Houghton said.