Michael Schumacher admits the death of Brazilian legend Ayrton Senna caused him to question his Formula One career.
Schumacher has won the first three races of the seasons
The six-time world champion is preparing for the San Marino Grand Prix at Imola - the 10th anniversary of the race in which Senna was killed.
"It was an awful weekend and a major shock for us all," Schumacher said.
"It was the first time that I had been confronted by death in my sport and for a while I doubted whether I wanted to carry on at all."
Schumacher, speaking on his personal website, added: "Senna was a symbol for Formula One and did so much for the sport."
Three-time world champion Senna suffered a high-speed crash at Imola on 1 May, 1994, and died in hospital later that day at the age of 34.
Austrian rookie Roland Ratzenberger died the previous day in qualifying in what proved a tragic and defining weekend for F1.
Schumacher added: "I think Max Mosley (president of motorsport's governing body) rightfully said that F1 became safer owing to him (Senna) and also Roland. That is the only positive that one can perhaps take from these tragedies."