A Toronto Transit Commission worker who was in critical condition after being caught between two vehicles at McCowan Yard in Scarborough on Oct. 1 has died.

The TTC said in a statement that 50-year-old subway track maintenance employee Tom Dedes succumbed to his injuries Monday at Sunnybrook Health Sciences Centre, the same hospital where he was taken after the incident.

Dedes was injured shortly after 2 a.m. on Oct. 1 when offloading equipment from a TTC pickup truck with coworkers. He was pinned against the pickup by the tail swing of a workcar, the TTC said.

TTC CEO Andy Byford told CBC Toronto that Dedes died at 2:25 p.m. Monday after developing an infection that spread rapidly.

"We're all in a state of absolute shock," Byford said. "To have him pass so suddenly when it appeared he was through the worst has broken our hearts."

The transit agency described Dedes as an 18-year veteran employee and said earlier that he underwent surgery after the incident.

"On behalf of the entire TTC family, I send my deepest condolences to Tom's parents and his partner, Gina, at this very difficult time," Byford said in a statement. "Our thoughts are also with Tom's co-workers as we all come to terms with this tragic and shocking event."

Mayor John Tory also expressed his condolences in a separate statement.

"The city will make sure we understand what happened and will take whatever steps we can to make sure a tragedy like this never happens again," Tory said.

Byford added that the TTC will only be doing safety critical and track work Sunday night to allow Dedes' colleagues to process the loss.

"It's a very close knit family — the track workers," Byford said. "They know each other very well, so we're making sure they are fully supported tonight."

Investigations by the Ontario Ministry of Labour and the TTC are ongoing, and the transit agency says it is fully cooperating with the ministry to prevent similar incidents from happening in the future.

"It certainly was a freak accident," Byford said. "We certainly can't understand how this could have happened.

"We will leave no stone unturned in making sure that we understand what happened here and taking action to prevent a recurrence."