One young boy was saved, but police and firefighters were still searching for a second boy after both plunged through the ice on the Red River in Winnipeg.
Constable Natalie Aitken says a motorist noticed the two boys playing on the ice near the Disraeli Bridge on Saturday afternoon when they fell into the water.
The motorist, Kole Duvisscher, told Winnipeg radio station CJOB that he saw something suspicious as he was driving by and glanced down at the river.
"I saw what looked like someone struggling to get back onto the ice," he said.
"I wasn't too sure and I put the truck in reverse and I backed up to see if it actually was someone and it turned out to be a little boy."
Mr. Duvisscher, who was driving with a friend in his father's truck, told his friend to call 911 and he scrambled down to rescue the 10-year-old boy.
"My dad has a tow-strap in the back of the truck so I just took that down because I wasn't going to get too close to the edge of the ice," he said.
"I threw it to him to try to get him to grab onto it. I looped it around to so he could put it over his shoulders because I knew he probably wouldn't be able to hang on to it too well."
Mr. Duvisscher says he never saw the second boy while rescuing the 10-year-old.
"He was screaming 'my brother's dead - he's gone.' I looked around and I didn't see him."
Const. Aitken said searchers were concentrating on an area that extends about three city blocks downstream from the bridge.
Crews resumed the search Sunday using inflatable boats on the river, which Const. Aitken said was ice-covered but has some open patches.
The 10-year-old boy was taken to hospital in stable condition.
Mr. Duvisscher said he wishes he could have arrived just a few minutes earlier.
"It's cool being all thought of and all, but it would have been better if I would have been there like five minutes earlier and found the other boy."