More than dozen fire trucks from municipalities across Montreal's South Shore are battling a major fire at an industrial produce building in the Monteregie on Monday morning.

A fire broke out around 4 a.m. at Guinois RGR in Sainte-Clotilde-de-Chateauguay, about an hour southwest of Montreal.

The fire is believed to have started when a compressor exploded on the roof of a warehouse.

Temporary foreign workers living behind the structure were uninjured and their residences were not touched. There were no other injuries reported.

Sainte-Clotilde-de-Chateauguay fire chief Benoit Tardif said the structure is unsafe to enter at the moment.

"It's a big size," he said. "Inside the building, you have a basement, so it's not possible to go in."

The building was renovated four years ago.

Guinois RGR is a major producer of vegetables that are sold to major grocery chains, wholesalers, and markets in the U.S. It has been in business since 1893.

Fire on South Shore

-- with files from CTV News reporter Matt Gilmour.

-- more to come.