A major highway, several other thoroughfares and a key transit hub were flooded in Toronto as torrential rains washed over Canada's largest city Tuesday, causing power outages in multiple areas.

Toronto police said part of the Don Valley Parkway, which runs from the north part of the city into the downtown area, was closed due to flooding. They also said part of Lakeshore Boulevard, which runs along Lake Ontario, was flooded and closed.

Toronto Fire Services said it rescued 14 people from flooding on the highway.

“We're actively rescuing people that are trapped in their cars or on top of their cars,” Deputy Fire Chief Jim Jessop told reporters in the afternoon. “We are triaging based on life safety.”

Tima Nizomov was among those who got stranded on the Don Valley Parkway. The 26-year-old said he had to wait in his BMW, with water around him, until firefighters arrived.

“A lot of water came but...my car is stuck and that's it,” he said, recalling his decision to stay in his vehicle as water rose around him. “Firefighters helped me.”

Rapper Drake shared a video on Instagram that appears to show flooding at his mansion.

“This better be Expresso Martini,” he wrote about the brown water.

Ontario Premier Doug Ford said his basement was flooded.

At the heart of the downtown core, there was flooding at Union Station, a key transit terminus. Water was seen pooling on the floor of a main concourse and stores at the station were closed. Parts of the underground PATH network, which has retail and restaurants and connects to Union Station, were also closed due to flooding and stores lost power for a time.

Subway trains were not stopping at Union, the Toronto Transit Commission said in the afternoon, while several transit buses and streetcars were making detours on their regular routes across the city due to localised flooding.

Flooding also disrupted life in many other parts of the Toronto region, with the provincial police warning of flooding on parts of highways and local police forces urging caution.

The Toronto and Region Conservation Authority said that shorelines, rivers and streams should be considered dangerous. It said more than 10 cm (4 inches) of rain had fallen in pockets across Toronto.

Toronto Mayor Olivia Chow said the number of Toronto Hydro electricity customers without power was down to about 109,000 by late afternoon.