Your vote on this answer has already been received
In early October 2004, he was being treated for a pressure wound that was causing a systemic infection called sepsis, a complication that he had experienced many times before. On October 9, Reeve felt well and attended his son Will's hockey game. That night, he went into cardiac arrest after receiving an antibiotic for the infection. He fell into a coma and was taken to Northern Westchester Hospital in Mount Kisco, New York. Eighteen hours later, on October 10, 2004, Reeve died of a heart attack at the age of 52. His doctor, John McDonald, believed that it was an adverse reaction to the antibiotic that caused his death.