The deputy fire marshal is investigating a suspicious overnight fire that destroyed King's Auto Centre in Little Bras d'Or.
It is the second major fire for the business owner this year.
Linda King's house on nearby Johnston Road was destroyed by fire in the summer.
That fire is also under investigation.
Deputy Fire Marshal Doug MacKenzie was at the scene of the latest fire on Sunday afternoon, interviewing witnesses and examining the rubble.
A wire fence, yellow caution tape and a security guard kept curious onlookers from getting too close.
MacKenzie expects it will take a couple of days to determine the cause.
Nearby homes evacuated
All that remains of the King's Auto Centre & Parts Store, located next to Highway 105, is a partial wall holding up a blackened sign, said CBC's Yvonne LeBlanc-Smith.
An adjacent building that houses several small businesses was also threatened by the blaze, but does not appear to have suffered any damaged, she said.
Firefighters were called to the scene shortly before midnight, said Cape Breton Regional Police Staff Sgt. Paul Muise.
By the time they arrived, the building was completely engulfed, he said.
"The fire was quite a large fire," said Muise. "As a precautionary measure, some surrounding homes were evacuated," he said.
"The police did traffic detail while the fire services, Florence Fire Department, fought the fire."
No one was injured and by 3 a.m., the fire was under control.
The local volunteer fire department thinks the fire may have been deliberately set.
The auto centre building is a local landmark.
It was originally built to house a cop-op grocery store and sat vacant for a few years before King's Auto Centre opened a couple of years ago.