SHELTON — State environmental officials are conducting air quality testing and removing contaminated debris from the Star Pin building site and the surrounding area after a massive fire devastated the historic structures along Canal Street last weekend.

The fire broke out about 7:30 p.m. Saturday, destroying the former Star Pin building at 273 Canal St., and a neighboring structure. A plume of dark smoke — along with debris, much of which contained asbestos — pumped into the sky for hours.

“The air quality results have been less than the (state Department of Energy and Environmental Protection) action levels,” said DEEP supervisor Jeff Chandler. “We are monitoring for solid particulate, total fibers and asbestos fibers.”

The cause of the fire remains under investigation.

Chandler said technicians are still compiling data about the health risk for those living, walking or working near the site, considering the large amount of contamination. He expects state environmental officials to be on-site until some time next week.

Initial calculations, according to Chandler, had the debris field extending past Route 8 southbound, with the total area being some half to three-quarters of a mile wide.

“We have 40 technicians dealing with asbestos (in the surrounding area) … and another 15 on the property recovering the various chemicals that had been stored there,” said Chandler.

Chandler said any residents with concerns regarding debris found on their property from the 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.

Firefighters have remained on-site since the blaze, putting out numerous flareups. Overall, Shelton Deputy Fire Chief Paul Wilson said, crews have used some six million gallons of water and are staying in contact with Aquarion to not overtax the system.

While flare-ups and hot spots had been issues, Wilson said, amazingly, there were no new flare-ups Wednesday.

“As of right now, we are not too sure when we will terminate our duties,” said Wilson. “DEEP is still on-site conducting air quality testing, and everything seems good so far. The demolition is going smoothly.”

A large crane arrived Monday evening as ACV Enviro supervised the demolition of the building, the roof of which collapsed during the fire.

The Star Pin building had been vacant for years, and no power was active on the site.

Wilson said fire crews will remain during the demolition and douse any flare-ups as material is moved. Firefighters can see smoke and embers, but since the floors “pancaked” in the collapse, the materials are sitting on top of smoldering areas, making it impossible for crews to reach potential hot spots, he said.

brian.gioiele@hearstmediact.com