A six-year old boy has died after drowning in the outdoor pool of an apartment complex in St. Leonard on Sunday. 

He was with his mother and sister before tragedy struck. 

At around 7 p.m., visitors told the lifeguard that a boy was unconscious at the bottom of the pool. 

The lifeguard jumped in and tried to revive him by performing chest compressions.

The boy did not survive. 

Witnesses were shocked and saddened. 

"I just saw the little boy on the floor and he was trying to breathe and they was pumping the heart so he never came back," said Diane Lambert, who was at the pool. 

The apartment's administration wouldn't speak about the tragedy.

The Régie du bâtiment oversees building regulations in the province.

According to their rules, small pools like the one the boy drowned in only need one lifeguard on duty.

However, when more than 50 people are in the swimming area, at least two lifeguards must be present. 

It's not yet known how many people were in the pool when the boy drowned. 

"it's very hard for the lifeguard to see all those patrons at the same time," said Raynald Hawkins of the Quebec Lifesaving Society. "A drowning situation for kids is only 15 to 20 seconds. It's very silent."

The family had only been in Canada for three months. 

A coroner is now investigating to determine if all the rules were followed.