(CNN) -- A power outage in Toronto, Canada, Monday afternoon left some 200,000 customers without electricity, stalled electric-powered passenger trains between stations and stopped much of the city's downtown, authorities said.

"Four hundred people from three trains had to be evacuated (after the trains lost power)," said Jessica Martin, spokeswoman for the Toronto Transit Commission."All the passengers were removed safely from the trains."

Officials blamed the outage on a fire at a transformer station.

The fire and subsequent outage occurred at 4:44 p.m. ET, officials said.

The outage was affecting a large part of downtown Toronto, said a representative from Hydro One Corporation, the city's electricity provider.