Downtown Toronto hit by major power outage, about 10,000 in the dark

Thousands are without power in downtown Toronto amid a Hydro One outage and the utility says it is "all hands on deck" to determine the cause.

Hydro One spokesperson Tiziana Baccega Rosa tells CBC News the utility is experiencing an outage on its transmission system that's affecting supply to Toronto Hydro and customers in the downtown core. 

"We have all hands on deck to understand the cause and to re-route the power as quickly as possible," Rosa said.

Toronto Fire Services says it's had at least a dozen elevator rescue calls throughout downtown as a result of the outage so far.

Many office buildings in Toronto's financial district and Toronto Metropolitan University's campus have lost power, and several traffic lights are out. 

Toronto Metropolitan University advised a majority of people on campus to evacuate immediately, saying the outage may compromise some building safety systems, such as fire detection and sprinkler systems.

All classes, labs or exams at the TMU campus are expected to pause during the evacuation. The school has advised employees to find an alternate place to work or take a break nearby until the outage has been resolved.

The TTC says it's experiencing major delays near Broadview Avenue at Dundas Street East on the 505 Dundas due to the outage.

Metrolinx says there's currently no impact on PRESTO, GO Transit or UP Express services, and Union Station still has full power. It says it's monitoring the situation and will keep customers updated if services are impacted. It also says it has back-up generators if needed.

Police say the cause is currently unknown and are reminding people to treat intersections as four-way stops if traffic lights are out.

More to come.