Subway train service on all four lines was suspended after the radio system train operators use to communicate with the control room failed entirely, the Toronto Transit Commission says.
Trains were holding in stations on the Yonge-University-Spadina line, the Bloor-Danforth line, the Sheppard line and the Scarborough RT, as crews rush to restore radio service.
"If we can't communicate with our subway trains, we can't run service," TTC spokesperson Brad Ross told CP24. He said all communication systems, including telephone and internet service, have failed at the service's central control centre. Ross said they were not sure what caused the radio outage.
Officials began closing off access to subway stations to keep passengers from overcrowding them. Shuttle buses will not be running to replace shuttered subway service, TTC officials said. Ross said he was not told why the Commission could not run replacement surface shuttle buses.
By 7:15 a.m., the TTC was able to resume service on the Scarborough RT between Lawrence East and McCowan stations.