Marimón was killed on 31 July 1954 during practice for the 1954 German Grand Prix, becoming the first driver to be fatally injured at a World Championship Grand Prix other than the Indianapolis 500. His Maserati left the Nürburgring race course at the Breidscheid curve near the Adenauer Bridge after he lost control attempting to improve his qualifying time. He died at the bottom of a steep and treacherous incline. He was going fast on a downgrade but failed to negotiate a sharp turn at the bottom. Marimón impacted a ditch, his Maserati shearing off a tree and rolling over a number of times. He was pinned underneath the car as it came to rest on its top with the wheels spinning in the air. Marimón was given the last rites by a Catholic priest before dying a few minutes after rescue workers freed him. It was thought that his braking unit failed.