Winds whipped up a wall of ice into a lakeside community in Canada's western Manitoba province, destroying or damaging dozens of cottages over the weekend, officials said Monday.
The ice sheet was up to nine metres high at some places when it crashed into homes at Ochre Beach, about 300 kilometre northwest of the provincial capital Winnipeg.
Twenty-seven cottages were destroyed or heavily damaged, including seven lived-in year-round, the town said in a statement, declaring a local state of emergency, but nobody was hurt as winds peaked at 90 km/h.
Jay Doering, a University of Manitoba civil engineer who studied ice mechanics, told AFP the seemingly bizarre occurrence is actually not rare, calling it an "intermittent event."
The same event happened in Alberta province and in the US state of Minnesota over the same weekend, he noted.
"You just need the right conditions: offshore ice, not a big sheet but smaller particles, and a big wind," he said.
Typically, gusts of wind push the ice toward the shore, it gains momentum, and once it reaches land "it just plows through, but because there's still more ice behind it and this area has a gradual shoreline, it kept shoving onto the beach or rolling over itself."
"It's called 'ice-shoves,"' he said.
"It's a little bit like having two trains on a track, one is stopped and other is coming in at full speed, and when the locomotives collide, the cars just keep coming in behind and continuing to add to the wreckage," he said.
In this case, however, the ice moved at alarming speed, he said, noting that the whole event lasted only 10-15 minutes.
Insurance companies won't cover the damage, and so residents are said to be hoping government disaster relief will help to defray some of the rebuilding costs.