The 1955 Le Mans disaster occurred during the 1955 24 Hours of Le Mans at the Sarthe circuit in Le Mans, France, on June 11. At 6.26 pm local time, two hours and 26 minutes into the race, the Jaguar of Mike Hawthorn approached and slowed down to the right side of the start/finish straight for his pit stop. Hawthorn's Jaguar was using the more advanced disc brakes, which slowed the car down faster compared to the drum brakes the majority of the field were using. Hawthorn swerved onto the path of the Austin-Healey of Lance Macklin, who immediately swerved left but was in the path of the Mercedes of Pierre Levegh. Levegh rear-ended the Austin-Healey at about 125 mph (200 km/h) and was launched into the air, before landing on the embankment that separated the spectators and the track. Pieces of debris from the car flew towards the grandstands at high speed, including the engine parts and the car hood, which decapitated spectators "like a guillotine". Levegh was thrown out of the car and died instantly from skull fractures upon impact with the road. Levegh, however, was able to warn his team mate Juan Manuel Fangio before the collision by raising his hand, which probably saved Fangio's life.
As the Mercedes landed on the embankment, the fuel tank ruptured, causing the car to burst into flames, setting its magnesium-alloy body alight. Rescue workers were unaware of the nature of the fire and only intensified it, resulting the car burning for several hours. Macklin's Austin-Healey veered towards the pit wall upon impact, narrowly missing several racers before bouncing back to the left side of the track, and Macklin climbed out unhurt. In all, 83 spectators, alongside Levegh, died from the crash, with a 180 more injured. Despite concerns, the race went on, citing that the large crowds leaving would affect medical and emergency services from arriving. Past midnight, out of respect for the victims, Mercedes, having been running in the lead and in third respectively, withdrew from the race, eventually leaving Hawthorn to win the event.
The disaster left a huge impact in motorsport, particularly safety. Several countries temporarily banned motorsport in their nations, in particular Switzerland, which banned motor racing completely, but was partially lifted in 2015 only for electric vehicles, such as Formula E. Three races in the 1955 Formula One season and also several races of that year's World Sportscar Championship were canceled. Mercedes, having planned to withdraw at the end of 1955, won that year's constructors' championship and subsequently withdrew as planned, not returning to motor racing for several decades until the 1980s. The circuit was redesigned and modified to improve safety standards, and John Fitch, who was Levegh's team mate and was scheduled to take over his drive before the disaster became a safety advocate, with the likes of Jackie Stewart.