Seven-time world champion Michael Schumacher on Sunday said he was determined to get to the bottom of a brake failure that caused a dramatic crash and put him out of the Singapore Grand Prix.

The Mercedes driver said despite pumping hard on the brakes, he was unable to prevent himself from ploughing into the back of Jean-Eric Vergne's Toro Rosso in a smash that left his car partially airborne.

The most spectacular collision of an incident-packed grand prix put both drivers out of the race on lap 39.

"At one point I couldn't accelerate and then I went hard on the brakes and tried to brake as hard as was possible, but the accident wasn't recoverable," Schumacher said.

"Obviously I feel sorry for Jean-Eric... but we need to find out what happened."

Vergne, who sportingly put his arm around Schumacher after the crash, called it a shame but refused to be angry with the veteran German.

"I was pretty focused on overtaking (Sauber's Sergio) Perez. I had a good move on him and at the end, braking, I just got hit by Michael," he said.

"It's done, I have nothing to say. It's just a shame. It doesn't make any sense to be pissed off about it."

The crash prompted the second safety car of the race, after a mishap involving HRT's Narain Karthikeyan. There were several other near-misses and McLaren's Lewis Hamilton was forced out with a mechanical problem while leading.

The race was preceded by a sombre minute's silence for Formula One doctor Sid Watkins, who died this month and was credited with vastly improving safety standards in the high-speed sport.