Cleanup continues in downtown Kitchener following a massive water main break that flooded an entire block Thursday.

The break left thousands of homes and businesses in Kitchener and Waterloo without water pressure for hours.

Regional officials say it was a significant pipe that was hit, measuring about 600 mm wide, which carries a huge supply of water through the system.

It was hit during construction at a site near Charles Street East and Madison Avenue.

“We saw the pressures dropping at our operating facility in the region and our Mannheim water treatment plant around 7:20 a.m.,” explains Nancy Kodousek, director of water services for the region.

Drewlo Holdings is the developer of the site. The company says a shoring contractor was drilling near the break, but all necessary approvals and locate requests were in place.

They’re working with the city to investigate the break and assess the damage.

Crews were back to work Friday morning, but many questions remain about how one break could cause such a significant outage—water-loss was even reported in parts of Breslau.

“The water transmission mains do not have service connections so they don’t actually connect to businesses or residences,” she explains. “They connect to what we call dual mains, or the local municipal distribution mains to provide water.”

The region’s investigators are still determining how the repair on the broken pipe needs to be done. Insurance investigators are sorting out who is responsible.

It’s still under investigation, meaning that the region does not yet have an estimate as to the cost.