SHELTON — State environmental officials are sampling debris from the massive fire that tore through two vacant structures — one of which was the historic Star Pin building — on Canal Street on Saturday night.

Shelton Fire Deputy Chief Paul J. Wilson said Sunday that fire crews were still operating on scene of the blaze, which started about 7:30 p.m. on Saturday. Wilson said the bulk of the fire was knocked down in about 3 to 4 hours.

“The scene remains very active with emergency personnel as suppression efforts continue,” said Wilson, adding that approximately 150 firefighters were on the scene throughout the incident.

“The exact potential environmental hazards are unknown at this time,” said Wilson, “however DEEP (the state Department of Energy and Environmental Protection) is in the process of sampling some debris. As of now, based on the age of the building, asbestos is something being evaluated.”

Any residents with concerns regarding debris found on their property from last nights Canal Street factory fire should contact DEEP at (860) 729-4677 or the Shelton Police Department at (203) 924-1544. Fire officials ask residents to advise them of the location of debris on the property and ask that no one touch debris until samples are gathered by DEEP or otherwise instructed by certified personnel.

Wilson said the Star Pin building, at 273 Canal Street, and another neighboring structure were destroyed by the fire.

No injuries were reported.

Shelton Mayor Mark Lauretti was meeting with state and federal officials Sunday morning about the future of the site. Lauretti said the city has agreed to sell the 145-year-old building to a Bridgeport-based developer, Primrose Companies, to convert it into residential units.

When Shelton firefighters were dispatched, Wilson said, the first units confirmed that the six-story vacant brick building on the banks of the Housatonic River was well involved in fire.

“Crews were advised from (Shelton Fire Chief) Fran Jones that the fire would be attacked in a defensive mode only,” said Wilson. “Ladder trucks and master streams are being used to apply water to the fire.”

As a precaution, Wilson confirmed, the former Avalon Shelton apartment complex was evacuated.

Derby fire units also responded to help with the blaze, with Ansonia fire units covering the Shelton downtown station and Monroe covering Shelton’s White Hill fire station.

“It’s bittersweet,” said Lauretti about the massive blaze. “We lost a part of history.”

In his near 30 years as the city’s mayor, Lauretti said, the city has endured some 15 major fires, many along Canal Street.

“People think that everything will stay the same, but there is always change,” said Lauretti. “My philosophy is to be part of the change. You can’t complain about it … you have to be ready to react to it.”

Wilson said firefighters faced not only the fire, but also the challenges of reaching the site, with only one real accessway down Canal Street.

“With limited access to the building and the volume of fire that was present, crews used portable master streams and aerial monitors to apply water to the building,” said Wilson.

Lauretti credited fire crews, who he called the “value of the Valley. This is what they always do … they always answer the call. Last night was a classic example of that.”

In March, the city of Shelton agreed to sell the former Star Pin factory to Primrose Companies, which offered $500,000 had plans to purchase a neighboring lot for parking.

Shelton had also approved reconstruction of the property for residential purposes with for 72 units and 128 parking spaces.

Last year, the state Department of Economic and Community Development approved a $750,000 grant for remediation of hazardous building materials at the site. The grant money was being used to remove lead, PCBs and asbestos from the 118,000-square-foot building.

Over the past 30 years, the property housed a variety of manufacturing firms, some of which conducted plating operations. The property has been largely vacant over the past 15 years and age and weather are beginning to exact a toll on the building’s structural integrity, officials said.

The Star Pin company was founded on Sept. 25, 1866. Its first location was along the Far Mill River in the Wells Hollow area of Shelton. The company moved to Canal Street in 1875. After more than a century, the company closed its doors in December 1977.

The company manufactured pins, hair pins, hooks and eyes for clothing. Star’s peak came during the 1920s, when 400 employees toiled there. By the early 1950s, the company also produced folding paper boxes and numbered 140 employees.

According to ConnecticutMills.org, one of the founders and early officers of the company, James C. Hubbard, is credited with inventing one of the first automated hair pin making machines in the United States.

Hubbard’s son, Henry Franklin Hubbard, joined the company during the 1890s and was active with the firm for 57 years. During this time he attained the title of “dean of American pin makers,” after designing the machine that produced the first “bobby pins.”

Tara O’Neill and Jim Shay contributed to this story.