Rain mars Canadian GP

Hamilton crashes out after clash with team-mate Button

Red Bull's world champion and pole sitter Sebastian Vettel was leading when the race was red flagged and cars ordered to park on the starting grid as rain lashed the across the Circuit Gilles Villeneuve.

The race was the first run in wet weather this season, making the twisting and challenging layout all the more treacherous.

"It's just way too dangerous, (FIA race director) Charlie (Whiting) has done the right thing to stop the race," said Red Bull team boss Christian Horner. "In conditions like these, drivers are just absolute passengers.

"The water picks the car up, they've got no drive and an accident is so easy to have, especially with the walls so close".

The wet conditions resulted in the first safety car start of the season, with the car staying out for the first four laps.

The conditions, with heavy spray and standing water, made for a tough afternoon for drivers with cars skidding and spinning out around the circuit. "It's undriveable, undriveable," Vettel said over the team radio.

"The conditions were extremely difficult. I thought they'd red flag it a lot sooner. Even before the race started the conditions were bad. I think it will be a long time before the race starts again," Force India’s Paul di Resta said.

Lewis Hamilton's bid for a Canadian hat-trick, after winning twice before in Montreal, had already ended after just eight laps when he collided with McLaren team mate Jenson Button.

Hamilton, twice a winner in Montreal in three visits, was attempting to overtake Button along the pit straight when they touched and he was squeezed into the wall damaging the left side of his car.

"What's he doing?" Button asked in amazement over the team radio while Hamilton parked his damaged car on the track, bringing out the safety car.

"Jenson made a mistake into the corner and I got the run on him, I felt I was halfway up the outside, but he kept moving across -- whether or not he saw me I don't know, but then I was in the wall," Hamilton observed.

"It was tricky conditions, I was doing the best I could to keep the car on track," Hamilton told BBC television after the race was later stopped by the teeming rain.

Stewards, who have seen Hamilton repeatedly already this season, said they would investigate the collision after the race. McLaren assured Button that his car appeared to be undamaged.