The contractor blamed for the closure of a large section of the Yonge subway line in Toronto on Wednesday might be getting a bill from the city.

Coun. Adam Giambrone, the TTC chairman, says the system's response to the shutdown of part of the Yonge subway line went 'incredibly smoothly.' (Robin Rowland/CBC)

A construction crew working for Enbridge accidentally sliced through a section of a subway tunnel just south of St. Clair station on Wednesday afternoon.

The Toronto Transit Commission, fearing the structural integrity of the subway tunnel was compromised, shut down the line between Bloor station and Eglinton station for about six hours while repair crews rushed to fix the problem.

Coun. Adam Giambrone, chair of the TTC, said the costs associated with the accident shouldn't be on the public's dime.

"And I did get a call from Enbridge this morning apologizing for the action," Giambrone told CBC News on Thursday.

"We'll continue to evaluate to see how we're going to recoup these costs and who in fact is responsible — clearly not the TTC — for the overtime costs and any costs it [took] to repair the tunnel."

The TTC had to pay overtime to the drivers of 50 shuttle buses brought in to ferry people up and down Yonge Street. The commission also had to pay maintenance crews to fix the glitch.

Giambrone estimated that overtime costs alone could come to tens of thousands of dollars.

The cost to repair the tunnel is still unknown, and it could take TTC engineers several days to survey the damage.

An estimated 300,000 commuters had their travel plans disrupted and they clogged Yonge Street on foot or in buses. The TTC resumed full subway service on the Yonge line at about 8:30 p.m.

Emergency plans questioned

Some who were caught in the confusion of Wednesday's subway shutdown are questioning the TTC's emergency plans.

Nearly 24 hours later, Loreen Lalonde was still upset over what she called the "mayhem" at the busy Eglinton station and her inability to get information after the subway line was shut down.

What angered her wasn't the construction accident that closed the line but the lack of Toronto Transit Commission staff to handle the crowds and pass along information.

"Several elderly ladies with canes asked for my help as they, too, had gone down and up stairs and could not find the promised southbound shuttle," Lalonde told CBC News.

The Toronto businesswoman said that what happened in the subway system would have been handled differently in the private sector.

"I come from the hotel industry and whenever there's a crisis or a situation such as this, all the management — everybody — goes down to where the public areas are, and everybody's there directing everybody," Lalonde said. "And I don't understand why there wasn't special constables, TTC personnel or signage."

Giambrone told reporters the system's response to the shutdown of the city's busiest subway line went "incredibly smoothly."