Environment Canada has confirmed a tornado struck Lachute Wednesday.
Resident Bruno Langevin recorded video of what appears to be a "jumper" tornado -- a windstorm that repeatedly forms and dissipates.
Meteorologist Amelie Bertrand said the video is definitive.
"The debris we saw from the pictures and the video that people sent us, it does look like a tornado," Bertrand said. "Now, we cannot say how strong it was. That's what the team is trying to find out."
The mayor of Lachute, Carl Peloquin, says 310 homes were damaged, all along a straight line about four kilometres long.
"In that line all the trees are gone, houses, roofs, you have pools upside down. It's a big mess," said Peloquin.
He said that a temporary shelter was set up for the residents of 20 homes who were not able to spend the night at home.
"It's a big mess, but we are getting back in control. No one was hurt so that is good news," said Peloquin.
"Last night we had about 50 percent of the homes without power."
The mayor said he was shocked by what he had seen as he went around town and inspected the damage, saying dozens of homes may be beyond repair.
"We don't have any history in Lachute of tornadoes. I've never seen that at all," said Peloquin.
Public Security Minister Martin Coiteux said that officials from the ministry had arrived in Lachute Tuesday evening.
"We are there to co-ordinate events," said Coiteux. "The town can also count on the direct financial support of the ministry."
"The magnitude of the damage, especially in regards to the overall population in Lachute, will require more financial help than Montreal and we will be there," said Coiteux.
Lorraine Girard was home with her grandchildren when fierce winds ripped apart her deck, her shed, her pool and her gazebo, but fortunately nobody was hurt.
"Around six o'clock I was in the house, my window in the living room started shaking and I had two of my grandsons with me, and I said something bad is going to happen," said Girard.
"My window in the kitchen opened and things started spinning around."
Her gazebo was blown across the street, and a neighbour's garage is now sitting in her yard.
"I don't care about that, because my grandsons were with me," said Girard, crying as she recounted the frightening memory.
"I didn't move. I had my baby in my arm and the other [at my feet] and [my husband] told me 'go dowstairs,' and I was not there. I just saw things going around and I didn't move," said Girard.
As quick as it began, the storm ended.
"Thirty seconds, and it was all done," said Girard, pointing to the devastation in her backyard.
This particular storm struck around 6:10 p.m., three hours after a microburst struck the Montreal borough of CDN-NDG.
Lachute was one of the regions that was under a tornado watch earlier in the day.