MONTREAL - The union for construction workers at the site of the French-language super hospital is raising safety concerns after a worker was critically injured two weeks ago.

Serge Provost was on a platform between the fourth and fifth floors of the CHUM site Jan. 12 measuring for windows when a chunk of ice fell from the 15th storey.

"The helmet exploded, from the information that we have, and actually it just shows how hard he was hit by the ice," said Eric Arseneault, a spokesman for the Commission de la santé et de la sécurité du travail du Québec (Occupational Health and Safety Commission).

Provost was taken to hospital in critical condition and placed on life support. His union says he should have been better protected.

"Usually, when there's (that) kind of work there's supposed to be a secure area around where you're working and there wasn't any," said Yves Ouellet of FTQ-Construction.

But just two days after the accident the workplace health and safety board says there was another problem involving ice. And Provost's accident wasn't the first time there's been a problem at the CHUM site, though it is the most serious.

In August, a steel pipe being lifted in to place fell to the ground, damaging a near-by taxi. A few months later, in November, freshly poured concrete spilled out of a mold and cascaded to the ground smashing car windows and sunroofs.

"Is it safe after four incidents like that? I'm not sure," Ouellet said. "I hope that they're doing what they have to do."

The CSST says it's keeping a close eye on the building contractor and steps have been taken to ensure workers are safe.

"Not only we ask them a safety procedure related to the works that are done on top of another but also we ask them to remove the ice in order to prevent again another accident like the one that happened to Mr. Provost," Arseneault said.

The contractor would not agree to an on-camera interview with CTV Montreal's Derek Conlon, saying only that it is cooperating with the CSST investigation and that security is a priority.

CSST figures show there are 19 accidents every day on Quebec construction sites.

Construction workers represent about six per cent of the work force, they represent a quarter of all workplace deaths, according to the FTQ.