Halifax officials say a massive water main break in a suburban neighbourhood may have been the cause of a second break, which created a sinkhole large enough to swallow a car.

The first water main break took place around 2 p.m. on Thursday in the area of Lennox Drive, Riverside Drive and Maple Grove Avenue in Lower Sackville, N.S.

At least five houses there had significant flood damage, after muddy water poured into homes and basements at pressures strong enough to break windows or crumble away driveway concrete, as some residents experienced.

Later that evening, at 9 p.m. on nearby Aspen Crescent, water came to the street surface again, opening up a sinkhole that briefly terrified a passing motorist.

“A sinkhole was created across the road, and a lady happened to be just driving by and ended up going forward into the sinkhole,” recalled Lorraine Bellefontaine, who lives nearby.

The woman was helped out of her car, which Halifax Water employees later pulled out of the hole. She wasn’t hurt.

Halifax Water says one water main break may have caused the other.

“It was quite a significant water main break in terms of flow,” said Reid Campbell of Halifax Water.

“Any time you get an event like that, there are flow changes and pressure changes in the system, so it's possible the second one was related a little bit to the first one,” he said.

On Friday, as work proceeded to fill in the sinkhole and repair the road, homeowners and insurance adjusters were left to tally the damage.

For one homeowner whose basement flooded, that damage is estimated to cost between $30,000 and $50,000.

John Scott came home to a flood after the first break, involving a nearly 36-centimetre water main.

“(The water) was about 18 inches high, and on the right side of my house it went right up to the door,” said Scott.

That first water main break left lots of standing water behind, with some residents reporting water about 60 centimetres deep.

Crews had to turn off water service in the area and call in heavy equipment to repair the break, leaving some residents without running water for several hours.

Denise Li was in her backyard with her dogs when the first water main broke.

“I could hear like a waterfall, so I kind of looked at the back two houses over, and I just noticed water gushing off of his side deck,” she said.

Neighbours scrambled to cut channels for the water to drain.

By Friday evening, the breaks had been fixed and waters service restored.

But what remains is a reminder of what damage can be done when frost heaves move the ground, making this the time of year when incidents like these happen most.

With files from CTV Atlantic’s Ron Shaw