ROCKLAND – A landmark waterfront restaurant and bar was destroyed by fire early Friday morning.

Grapes Restaurant, which this summer took over the location of what had been the Black Pearl restaurant and bar on a pier near the city landing, was discovered burning sometime after midnight.

Rockland police had gone to the nearby Time-Out Pub on a fight complaint when someone came inside the bar to say that Grapes was on fire, said Tim York, a senior fire investigator with the State Fire Marshal’s Office.

The fire was reported at 12:59 a.m., and firefighters were on the scene shortly after 1 a.m.

The fire was contained within an hour, but York and Rockland firefighters did not leave the scene until about 11 a.m. Friday.

The cause of the blaze could not be immediately determined.

“The damage is pretty extensive,” York said. “The dining area is pretty much gone,” with more damage attributed to heat, smoke and water used to fight the blaze.

The approximately 200-foot pier is owned by Frank Ferraiolo, and the restaurant is owned by Mike and Kate Miller, Rockland Assistant Fire Chief Adam Miceli said. Neither the Millers nor Ferraiolo could be reached Friday, though Miceli said Mike Miller came to the scene during the night.

The restaurant was believed to have been insured, Miceli said.

Three investors substantially rebuilt the pub in the summer of 2001, after the Black Pearl had closed its doors five years earlier.

The restaurant closed for the season in October, “but there’s been people in and out in various capacities” since, he said. An office in the building had been used, Miceli said.

Both York and Miceli said there was no evidence of appliances left on, or of electric devices such as heat tape to prevent pipes from freezing in use.

Though high winds buffeted the area late Thursday night, the air had calmed considerably after midnight, Miceli said, which seemed to suggest that electrical service problems were not the cause.

York said investigators no longer term fires as “suspicious,” and would only say its cause was under investigation. Asked if arson was a possibility, he said, “There’s nothing that points in that direction, but there’s nothing that points away from that either.”

York said he knew that several apparently intentionally set fires have been reported in Rockland over the last several months.

“Obviously, we’re aware of that,” he said, and that might affect the investigation. As of Friday morning, though, there was no obvious evidence to point to arson, York said.

The fire started in the northeast, seaward side of the restaurant, he said.

No evidence was removed from the scene, he added, but he expects to talk to people involved with the restaurant as part of the investigation.

Some sections of the pier were damaged by the fire and are unsafe to walk on, York said.

Miceli said the rash of apparent arson fires over the last several months was on his mind after the Grapes fire.

‘”We’re obviously concerned because of the number of outside fires that seem to have been started by the human element,” he said. Miceli estimates that six or seven fires since the spring have raised his and the department’s suspicions, though “some of them don’t fit the same profile.”

The fires in question were started outside of buildings, he said, some in trash containers. Like York, Miceli was unable to determine whether the Grapes fire began outside or inside the building.

Though two-thirds of the building remains standing, “it’s pretty much a total loss,” he said.

The fire could have been a nightmare to fight, Miceli said, given that it was at the end of a wooden pier, where “there’s one way in, and one way out.”

The weather was not an obstacle, he said, with the wind blowing away from shore, so firefighters did not have to work their way through smoke. And the balmy temperatures meant there was no ice to contend with after the building was soaked by hoses.

“Who would’ve thought on December 24 it would’ve been 57 degrees?” he said.

About 40 firefighters were on the scene, and the Rockland department had assistance at the fire from Thomaston’s department, which brought its ladder truck. Rockland’s ladder truck is out of service, and the department is lobbying the City Council for a new truck.

Miceli said the Thomaston crew set up on the wharf where the Monhegan boat is docked, and kept it soaked with water to protect it from igniting.

South Thomaston’s department also assisted, Camden and Rockport departments covered the Rockland fire station in case any other fires were reported, and Camden First Aid also backed up Rockland.

St. George and Warren covered for Thomaston, and Lincolnville covered for Camden.

A firefighter suffered a first-degree burn on his face, but did not need to be taken to the hospital, Miceli said.

The Rockland department has been urging business and homeowners to keep their yards clean of debris, to keep trash containers away from buildings, Miceli said, and to keep yards well-lighted to discourage arson.