MONTREAL—A section of Ste-Catherine St. was partially reopened on Thursday evening after being closed over fears it might collapse.

On Thursday morning, work crews discovered a cavity under the road, forcing the closure of the important artery between St-Laurent Blvd. and Berger St.

The city has blamed a leaky brick water pipe built in the 1890s for the closure. Four metres under the road, the leaking pipe had slowly dug a cavity. The city had plans to replace the sewer.

Repairs will begin next week and will last about a month. During that time, the impacted section of Ste-Catherine St. will be down to one lane.