A swing set stands next to the section of Rideau River where a boy, 9, drowned Tuesday.

A nine-year-old boy has died after falling into the Rideau River in Ottawa on Tuesday.

Emergency crews pulled the boy from the water around 2:15 p.m., near Strathcona Park — an estimated 800 metres from where he fell into the water near Mann Avenue in Ottawa's Sandy Hill area.

Authorities said the boy was playing with a friend before the accident. When he slipped into the river, the other boy raced to get help.

Marc Messier, spokesman for the Ottawa Fire Service, said firefighters were launching boats when they spotted the boy's body. One firefighter, in full rescue gear, went into the water to get him.

"We didn't want him to float downstream any further," Messier told CBC News.

"We brought him to shore. It was determined his vital signs were absent, so we began CPR."

Paramedics continued efforts to revive the boy as he was transported to the Children's Hospital of Eastern Ontario.

He was declared dead in hospital.

It's not known how long the boy was in the water, paramedics said.

The boy has not yet been identified.

Messier urged people to stay off the ice covering ponds and rivers in the Ottawa area. He said fluctuating temperatures and high amounts of rains have made for fast currents that are weakening ice.

"We're urging people stay away from the sides and from the ice," Messier said.