Software issue to blame for halting of all trains along two major transit lines, TTC says

A Toronto Transit Commission sign is shown at a downtown Toronto subway stop Tuesday, Jan. 31, 2023. THE CANADIAN PRESS/Graeme Roy

The TTC has launched an investigation after a software issue resulted in the halting of all trains along two major transit lines on Thursday morning.

Service was suspended alo

ng the entirety of Line 2 and Line 4 just before 10 a.m., stranding thousands of riders. The TTC confirmed to CP24 at 10:30 a.m. that service was resuming with some residual delays likely.

The TTC said that approximately 200 shuttle buses were previously dispatched along the lines to supplement service.

In a post on social media on Thursday afternoon, the TTC said that it is now looking into what might have caused the software issue.

“Service was restored within 30 minutes. The Automatic Train Control system on Line 1 Yonge–University was not impacted. Operating safeguards remain in place as the investigation continues," the TTC said.