OXFORD - This wasn’t how Jim Smith planned to spend Father’s Day.

“I was supposed to go fishing yesterday,” the Boylston father of three said Sunday as he picked through computer equipment salvaged from his Oxford business, ravaged by fire on Friday night.

Mr. Smith and his brother, George, of Shrewsbury, are owners of the commercial building at 710 Main St. that sustained damages estimated at more than $1 million.

The three-alarm fire that was reported about 6:45 p.m. Friday.

On Sunday, the brothers, who operated three land-surveying businesses out of the building, were in the rear parking lot with their information technology consultant, Bill Blanchette of Charlton, taking stock of the office machinery they had been able to recover.

An antiques shop, Rust to Ruffles, also was located in the building, a former Knights of Columbus headquarters.

On Sunday, Don Parker of Oxford stopped by to see if any of the antique cups and saucers his wife, Sue, sells on consignment there could be salvaged, but he said he was not allowed in the building.

A gaping hole could be seen in the charred roof on Sunday afternoon as the Smiths took inventory on the server and other computers they use in their land surveying and civil engineering work, and which fire officials had given them permission to remove.

Nobody was reported injured in the fire. “Very lucky,” said Jim Smith. He said the one person in the building on Friday night smelled something burning and called the fire department after seeing smoke and flames coming from a dropped ceiling.

Mr. Smith estimated the damage to the building and the equipment and goods within at more than $1 million. The building likely will have to be torn down, according to fire officials.

The cause of the fire remained under investigation on Sunday, according to the Oxford Fire-EMS Department, and the state fire marshal was expected to return on Monday.

But an electrical malfunction is suspected, said Mr. Smith, pointing out a spotlight on the roof that had not been working in days prior, but was seen on at the time of the fire.

As it happened, the building owners were preparing in the next week to replace all the lights in the building in connection with a state energy-saving audit, Mr. Smith said. If indeed there were a flaw in the electrical system that led to the fire, it might have been discovered.

“This might have been totally avoided,” he said, looking up at the charred roof and the suspect spotlight. “All the new lighting equipment was sitting in the hall.”