A portion of Line 1 was shut down during rush hour on Tuesday after a contractor accidentally punctured a hole in a subway tunnel near Toronto's midtown.

Around 3 p.m., the Toronto Transit Commission (TTC) tweeted that there was no subway service on Line 1 between Lawrence and St. Clair stations.

An hour later, the TTC said that “personnel are currently investigating if construction in the area has infiltrated the subway tunnel.”

A spokesperson for the TTC said that a contractor was doing work at street level and punctured the top of the concrete subway tunnel. Crews worked to plug the hole with grout, something officials call a temporary repair.

Photos posted to social media show large crowds of people waiting to get on shuttle buses. Service resumed around 6 p.m.

Officials said that that portion of the subway will be closed again at 11 p.m. for more permanent repairs. It is expected to reopen at 6 a.m. on Wednesday.

The delay briefly impacted sport fans heading to Scotiabank Arena for the Raptors season opener.

About 70 shuttle buses operated between York Mills and St. Clair stations at the time of the closure.