The severe thunderstorms and heavy rainfall that pummelled Toronto and area Thursday night have claimed the life of a teen boy who was found dead in a waterway in a city park.

The unnamed teen and a friend were apparently exploring a storm drain in Earl Bales Park late Thursday when rising water levels and swiftly moving currents caused by the downpour swept the two through the underground system.

TFS, TPS, and TEMS crews were on scene from that point forward. A comprehensive search of the area was conducted. Sadly, crews located & recovered the deceased body of the missing person at approx 11am, Senior officers provided an update after family were notified. ^dv #Toronto

— Toronto Fire Services (@Toronto_Fire) August 25, 2023

Emergency personnel responded to the scene around 1:20 a.m. Friday after the other teen, who was able to cling to the side of the manufactured waterway, hoisted himself out and called for help.

The survivor had been holding on for about 30 minutes before he gathered the strength to climb to safety. 

After an extensive overnight search of the area that involved about 65 members of the Toronto Police Service and Toronto Fire, the victim — whose exact age is unconfirmed at this time — was found dead about half a kilometre down from where the duo were shot out of the underground chute into the river.

The waterway serves as part of the park's stormwater management infrastructure.

Teenagers adventure turns deadly.

Sad that a young man died. Storm drains can be dangerous when water levels rise due to rain. https://t.co/JeE6VRgo3u

— Gladys R. Bates 🇨🇦🇨🇦🇨🇦🇨🇦 (@GladysRBates142) August 25, 2023

Authorities are calling it a case of "misadventure," as the boys would have had to deliberately remove a manhole cover near the top of the Earl Bales ski hill to enter the 300 m tunnel, which they are thought to have been exploring.

Residents are reminded to stay away from high water levels, fast waters, "and the sewer system for sure," as they can clearly be deadly.