1994 was one of the most tragic and controversial seasons in the sport's history. The San Marino Grand Prix saw the deaths of Austrian rookie Roland Ratzenberger and three-time World Champion Ayrton Senna ("details"); while a number of other incidents throughout the season resulted in injuries to drivers, mechanics, spectators and a track marshal. The FIA subsequently made sweeping changes to the rules and regulations of F1 in an effort to improve safety. Schumacher won six of the first seven races, building a significant lead for himself in the Drivers' Championship and for Benetton-Ford in the Constructors' Championship; he was then disqualified from two races and banned from two more, Williams driver Damon Hill winning all four to reduce Schumacher's lead to a single point by the final race in Australia. There, Schumacher and Hill controversially collided while disputing the lead, handing the Drivers' Championship to Schumacher. 1992 World Champion Nigel Mansell, returning to F1 after two seasons in CART, won the race to secure the Constructors' Championship for Williams.