Mystic ― Fire officials said they expect to spend several days digging through the remains of a Seaport Marine warehouse and office building that burned to the ground in a spectacular blaze Sunday night.

Mystic Fire Chief Anthony Manfredi Jr., who also serves as fire marshal, said there is nothing about the fire that stands out as suspicious though it is still very early in the investigation.

“This is still very much an active scene. We have a lot of work ahead of us,” Manfredi said from outside the cordoned off fire scene at 2 Washington St. Monday afternoon.

The site was busy with activity all day Monday with firefighters snuffing out hot spots, investigators digging through debris and crews replacing burned utility poles as part of the effort to restore power to the homes and businesses in the immediate area. Homes and businesses on Cottrell, Washington and Willow streets were expected to be without power until Monday evening. A total of 158 customers lost power after the fire and 69 outage remained late Monday afternoon.

Manfredi called in the state’s Fire and Explosion Investigation Unit to help with the investigation into the cause of the fire at the sprawling commercial warehouse on the Mystic River.

The building complex that burned contained office space, a paint shop and was mostly used for storage, Manfredi said. Prestige Yacht Sales and Fighting Lady Tackle Co. both list addresses at 2 Washington St.

An adjacent home at 4 Washington St. also was damaged in the wind-driven fire that lit up the night sky shortly before 9 p.m. on Sunday. The occupant of the home and his dog safely evacuated before the fire started to spread, Manfredi said.

Manfredi said no injuries were reported though one firefighter was evaluated for smoke inhalation at the scene.

Amid the wreckage of the fire were burned shells of several boats, a vehicle and a forklift. Along with the wind, Manfredi said chemicals, fuel and propane tanks inside the building likely contributed to the size of the fire. The explosions and pops heard by nearby residents was likely the result of exploding propane tanks, he said.

Firefighters arrived Sunday night to find heavy fire at the front of the building. After calling for a fourth alarm, which brought in extra equipment and manpower from departments in the region, Manfredi said nearby residents were evacuated as a precaution.

The speed of the blaze was hastened by wind, which shifted direction and moved the fire through the warehouse. Four aerial fire trucks, supplied by water from hydrants and a fire boat on the Mystic River, helped to contain the fire as firefighters went into a “defensive mode” dumping water in the blaze from a safe distance.

Pat Ryan, who often brings his daughter to Cottrell Park which is across the street from Seaport Marine, said he watched the fire with a group of others from across the river on the Groton side of Mystic.

“It lit up the sky,” Ryan said.

Residents in the area said the orange glow of the flames from the fire could be seen for miles and was reminiscent of the 2000 fire that burned multiple businesses on West Main Street, a short distance away.

“The flames were sky high,” said Marjorie Wheeler, who was in town visiting her son.

She said the fire led to a loss of power where she was staying on Rosaleah Drive. Manfredi said the power was temporarily cut to a large area after firefighters encountered burning and falling wires near the fire.

“What scared me was the twisting flames, like a tornado,” Wheeler said.

Longtime Mystic Resident Fran Walenta said the buildings where the fire occurred used to be part of the Post Boat Yard, a boat building business and workshop. It later became Seaport Marine under the prior ownership of Malcolm Robertson.

Walenta said there is likely decades of paint and other boat building material built up on the wooden floors of the buildings and it likely contributed to the heat of the fire.

Seaport Marine is located at 2 Washington St. and part of a larger piece of property containing boat slips, several buildings, including Red 36 restaurant, now owned by the Holstein family under the name Waterfront Group LLC.

The 11.5-acre property, which some residents have said has become dilapidated in recent years, was at one point the proposed site of a a hotel, boardwalk and condominium development project called Smiler’s Wharf.

Harry Boardsen, general manager at Seaport Marine, did not return calls Monday seeking comment about the future of the property. Instead, Boardsen issued a statement through the Greater Mystic Chamber of Commerce thanking fire crews for their work to contain the damage.

“We are working to have the site cleared of debris as soon as possible. We are thankful for all the first responders for their efforts in containing the blaze and protecting adjacent property,” Boardsen said.

Chamber of Commerce President Bruce Flax on Monday thanked firefighters and said the chamber’s thoughts and prayers are with Seaport Marine. He also said that it was thanks to the efforts of the fire department that no injuries were reported and nearby homes or businesses were spared damage.

Flax said Mystic businesses remain open and the fire should not discourage people from visiting to support local shops and restaurants.

Tony Suarez, owner of Northern Light Gems that for decades was located in downtown Mystic, was at the scene of the fire on Monday and said it could have been worse.

“If the wind had changed, you might have lost half the town,” he said.

g.smith@theday.com