Subway service on a key stretch of Line 2 was shut down during the Wednesday morning commute due to a fire near Ossington Station, the TTC says.
There were no trains operating between Keele and St George stations, the transit agency said.
More than 40 shuttle buses are running.
Toronto Fire said a blaze was seen at track level at Ossington around 6 a.m. but had been extinguished by TTC staff by the time firefighters arrived.
The TTC said there is currently no estimate for when regular service may resume.
The latest subway problems comes as Environment Canada has issued a winter weather travel advisory for the city and surrounding areas. The federal weather agency says a cold front could bring periods of heavy snow and high winds, making for messy conditions on roads.
The transit agency also warned subway riders on Line 1 there may be 10-minute delays this morning while it fixes a signal issue that’s affecting service betweeen Dupont and Union stations.