The 1978 Italian Grand Prix at Monza started badly for Ronnie Peterson, 34 when in practice he damaged his Lotus 79 race car beyond immediate repair and bruising his legs in the process. Team Lotus possessed a spare 79, but it had been constructed for team-mate Mario Andretti, and the taller Peterson was unable to fit comfortably inside. The team's only other car was a type 78, last years car, which had been dragged around the F1 circus that season with minimal maintenance.
Come racing time, the grid lined up as normal. The race starter, however, was overenthusiastic and several cars in the middle of the field got a jump on those at the front. The result was a massive crush of cars up to the recently added chicane just before 'curva grande' corner and all hell broke loose. James Hunt collided with Peterson, with Riccardo Patrese, Vittorio Brambilla, Hans-Joachim Stuck, Patrick Depailler, Didier Pironi, Derek Daly, Clay Regazzoni and Brett Lunger involved in the ensuing melee. (Later on, Hunt, among other drivers, unjustly blamed Patrese for starting the accident, and viewers of Hunt's commentaries of Formula 1 races from 1980-1993 on BBC Television were regularly treated to bitter diatribes of Patrese when the Italian appeared on screen).
Peterson's poorly maintained and flimsy Lotus went into the barriers hard and caught fire. Though trapped, Hunt, Regazzoni and Depailler managed to free him from the wreck before Peterson received more than minor burns. He was dragged free and laid in the middle of the track fully conscious, his severe leg injuries obvious to all (Hunt later said he stopped Peterson from looking at his legs to spare him further distress). Scandalously, it took 20 minutes before the Italian circuit dispatched medical help to the scene. At the time, there was more concern for the Italian Brambilla (who as a matter of fact was born in Monza), who had been hit on the head by a flying wheel and was slumped comatose in his car (he later recovered and drove on in F1 until 1980). Peterson's life was not, however, seen to be in any danger. The injured drivers were taken to hospital in Milan and, after a major cleanup job, the race was restarted (for those with undamaged or spare cars at least).
At the hospital, Peterson's X-rays showed he had 17 fractures in one leg and 3 in the other. After discussion with Ronnie himself, the surgeons decided to operate to stabilise the bones.
Unfortunately, during the night, bone marrow from the fractures had got into Peterson's bloodstream forming fat globules on his major organs including lungs, liver, and brain. By daybreak he was in full renal failure and was declared dead a few hours later. The cause of death was given as fat embolism.
The tragedy was that Peterson's life would most likely have been saved had he received medical attention immediately after his accident.