Officials in Sault Ste. Marie are investigating a fire at the abandoned Mill Square building on Sunday evening.
Several trucks responded to the blaze in the Pulp Tower just after 5 p.m.
No one was injured, but officials are deeming it suspicious.
It's the third fire at the Pulp Tower site in the past two weeks.
“Right now we don't have any suspects in these investigations,” said Constable Sonny Spina, Sault Police Service.
“However, our officers are exploring if any of these fires are linked and if there are any suspects that we can identify.”
