WorkSafe New Brunswick is investigating a blasting incident that sent rocks hurtling into cars and windows in a parking lot in Saint John.

Northrup Group, which owns the East Point Shopping Centre, had hired Debly Enterprises Ltd. to blast rock near the TD Canada Trust. There was a detonation at about 4 p.m. on Friday.

That blast sent rocks — some of them the size of bricks — into the parking lot of the bank. Several cars were struck and the vehicles' windows were smashed.

"Nobody got hurt. No injury at all. Just a lot of damage — about 13 vehicles," said Laura Mae Slocum, a branch manager with TD Canada Trust.

"It's a miracle, really. We have no idea how nobody sustained even a hit with a rock."

Most of the damaged vehicles belonged to bank employees, who told CBC News they expect to be making a claim against Debly Enterprises Ltd.

Ron Buchanan, a health and safety officer for WorkSafe New Brunswick, said the blast was done by one of the city's most experienced technicians — a person with 35 years of experience.

"The blast was done by a certified blaster in the province of New Brunswick. He had done the holes and everything according to the standards that are set," said Buchanan.

"There was possibly a fault in the rock, which allowed the pressure of the blast to push the rocks out in this direction."

One rock slammed into the side of a bank and lodged into the outer wall.

Buchanan said the contractor was watching for human traffic and had stationed workers at strategic locations to make sure no one wandered into the danger zone.

He is imposing new conditions on the job from now on.

"I will continue to monitor the site on a frequent basis before any blast is conducted," he said.