A 17-year-old is being hailed as a hero after diving into a frigid pool and rescuing an 82-year-old man.

The elderly driver was sitting in his car behind Cavendish Mall when the vehicle shot across the parking lot and toward a house at the corner of Mackle Rd. and Newton St. in Cote-St-Luc.

"He suddenly had a health problem and the car started to move forward," said Montreal police Constable Andre Leclerc.

The car travelled 200 metres before smashing through two fences and plunging into a half-filled inground pool.

Marten Benko saw the accident while walking his dog.

He ran to the crash, tied up his dog, then stripped off his heavy clothes and jumped in.

"I looked at the car, like really quickly to see how many people are in the car," said Benko. "I only noticed like one person, he didn't seem to be moving in the passenger seat.

"The car at the front was like completely submerged meaning he was drowning at the moment - at the same time."

Benko used his elbow to smash his way in to the car and pull the man out.

When police officers and emergency workers arrived at the scene, they also jumped into the pool, fearing that the man's wife might be in the water.

They later discovered the woman was inside the shopping mall throughout the ordeal.

Marten's mother is very proud of her son

"Many people they get shock and they stay still and they cannot move, and he just did his job," said Maria Benko.

It's a job Benko has prepared for.

He has been swimming since he was six months old and won about 100 medals since he began competing at the age of eight.

He's also a lifeguard, but Benko admits the water was so cold when he first jumped in he wanted to get out, however he knew he had to get to the driver first.

Leclerc was among the police officers at the scene who were impressed.

"He had to break the back window of the car and he was able to retrieve it from the side doors. The guy made a hell of a job you know?" said Leclerc.

The victim is now in stable condition in hospital.

Police are investigating to determine exactly what caused the crash.