Heavy rains Tuesday night once again flooded underpasses in Montreal, creating problems for an ambulance driver whose vehicle literally floated in one underpass while he was on an emergency call in the Cartierville area.

In all, 40 millimetres of rain fell on Montreal Tuesday night.

In the underpass where De Salaberry Street crosses under Highway 15, the storm sewer couldn't hold all the runoff from the rain, so water gushed up through manholes and storm drains flooding the area.

Around 9:45 p.m. an ambulance driver responding to an emergency call thought he could drive through all that water. He was wrong. The engine stalled, and it wouldn't restart, as the water rose to the windows.

That's when things got worse.

"It was literally floating, bobbing from side to side, no longer touching the ground," said Urgence Santé spokesman Stéphane Smith in French.

"Water seeped in, damaging our equipment," he said.

Another ambulance was quickly dispatched to the original emergency call, Smith said.

He said the ambulance technicians were soaked, but otherwise unhurt.