Police west of Montreal are investigating what appears to have been a robbery that turned into the beating death of a construction company president.

Serge Loiselle and his wife were attacked in their home on Donat St. in Salaberry de Valleyfield around 9 p.m. Monday after burglars burst inside.

The criminals tied up the couple and beat them severely, then left.

The victims were taken to hospital as soon as ambulances arrived, but Loiselle succumbed to his injuries, while his wife suffered serious injuries but is expected to survive.

Loiselle, 57, was the president of Ali Excavation that operated out of Salaberry de Valleyfield.

Loiselle's brother and business partner, Normand, said he was consoling his employees who have been trying to determine why the attack occurred.

"It's emotional, and I also have to support my family and manage the business at the same time. I have to stay strong, and calm," he said.

Neighbours said they were also concerned about the attack.

"These things are always scary," said neighbour Martin Guerault. "We're anxious to find out what really happened, and we hope police will arrest those who are guilty."

An isolated street near a golf course, several surveillance cameras and a pair of spotlights are easily visible surrounding Loiselle's home.

The home also had a sophisticated security system, said a neighbour who wished to remain anonymous.

Police said they are exploring various theories, including that his line of work may have been linked to the attack. For now they say they're simply treating this crime like any other robbery.

"We're looking at the hypothesis of a theft. Is it related or not to his working as a contractor? We don't know for a fact that it is," said Surete du Quebec spokesperson Chantal Mackels. "Any time that somebody dies, we do a whole investigation about his life. Everything is going to be looked at."

Norman Loiselle denies any link.

"We discussed it with our lawyers, and concluded it was a robbery gone wrong," he said.