A 16-year-old boy has succumbed to injuries after jumping in to the lake at Woodbine Beach to try and help a mother and her young son who were in distress, Toronto police say.

Toronto police’s marine unit responded to the area, near Ashbridges Bay, at around 2:30 p.m. after lifeguards alerted them to three people “in distress” in the water.

According to Toronto police Const. David Hopkinson, a woman and her son went into the water and “became uncomfortable and called for help.” A number of people jumped in the lake, including a boy in his mid-to-late teens.

Police say the teenager was pulled under the water. He was eventually rescued and taken to the hospital in life-threatening condition, where he later succumbed to his injuries.

Two other teenagers were also transported to the hospital, paramedics say.

“I think there might have been some confusion,” Toronto police media officer Gary Long told CP24 via phone. “People at the scene who were doing the investigating and the searching advised that everyone was accounted for.”

After two people, a male and a female, were pulled out of the water, emergency crews then began a search for a third person who was reportedly missing in the water, but an investigation later determined that all victims had “been accounted for.”

Toronto Fire Chief Matthew Pegg said a total of five people needed to be rescued from the water.

The search and rescue effort, which involved a number of police boats and divers, was called off about two hours later.

“There doesn’t seem to be anything sinister here, just a tragedy” Hopkinson said.

At the height of the incident, ten fire crews and one fire boat were on along with multiple paramedics.

The coast guard was also called in to assist in the search efforts.

Pegg called the operation “very, very challenging” for first-responders.

“They’re challenging in any condition, but it is breezy today, you can see the waves. These are really, really tough operations. They’re physically demanding… They’re difficult on the rescuers,” he said. “Everyone is working so hard.”

Video from the CTV News Toronto Chopper showed Toronto police marine unit boats and search and rescue dive teams combing through the water near a rocky part of the shore.

Hopkinson told CP24 that only the “strongest of swimmers” should enter the water on the west side of the beach near the rocks.

“We have found that the water in the area of Woodbine Beach near the rocks has a very significant undertow and we are cautioning people not to swim in that area unless you are a very, very strong swimmer,” Hopkinson said.

“I believe incidents of this nature cause the mechanisms that we have for investigation and how we respond to tragedies, you know to maybe answer some of these questions. Of course it will be reviewed by the city and all the people involved once we are able to submit our report to the city.”