Icebreaking near Thunder Bay has stopped half-a-day after it began.
The ships Morro Bay and Katmai Bay started breaking up ice Thursday morning, but mechanical failure on the Morro Bay forced the two ships to head back to Duluth by the afternoon.
Thunder Bay Port Authority engineering director and harbour master Guy Jarvis said the ice is 28 inches thick, making for a difficult time.
"It's very hard and challenging. It may be a contributing factor to (Morro Bay's) current condition," he said.
It may delay the arrival of larger icebreakers like the US Coast Gaurd's Alder, as larger ships need smaller tugs to accompany them into the bay.
Heavier breakers are now expected around Tuesday.