The boy was found unconscious at the bottom of the Paul-Émile-Beaulieu community centre pool on Wednesday afternoon. (CBC)

An eight-year-old boy found at the bottom of a community pool in Quebec City on Wednesday afternoon has died.

The boy, found unconscious in the outdoor pool at the Paul-Émile-Beaulieu community centre, was resuscitated by lifeguards. However, his condition deteriorated overnight and he was pronounced dead in hospital shortly after 2 p.m. ET on Thursday.

The boy had been wearing a life-jacket when he entered the pool, according to his parent's instructions, but appears to have taken it off later, said city spokesman Jacques Perron.

He was pulled from the water after lifeguards were alerted by another child.

At the time, there were more than 100 people in the pool, which was being supervised by four lifeguards.

The number of lifeguards was appropriate and well above the number required by law, said Raynald Hawkins, director general of the Lifesaving Society's Quebec branch.

According to provincial laws regarding public pools, just two lifeguards are required to supervise up to 150 swimmers.

Four lifeguards would have been permitted to supervise a pool of 300 to 500 swimmers, he said.

The Paul-Émile-Beaulieu centre pool was reopened to swimmers on Thursday afternoon.

Pending the results of an investigation, Perron said the city may review its safety regulations.

Pool personnel as well as witnesses will be provided with psychological counselling, he said.