The fire is now contained and everyone is safe but at one point the flames were too close to explosive material. That forced evacuations and firefighters had to go use a drone to view the blaze from above.
A fire at a Branford quarry is likley to smolder for days, according to fire officials.
The fire started Thursday afternoon at Stony Creek Granite Corp. on Quarry Road in Branford.
Homes within a one-mile radius of the quarry were evacuated due to concerns about explosives being stored at the site.
Captain Geoff Morgan, of Branford police, said a phone message went out to all residents to alert them about the fire.
Blasting mats caught fire, but the main concern was over the explosives being stored near the fire scene, according to Branford Fire Chief Jack Ahern.
The fire appears accidental, and may have started because people burned cardboard boxes near the blasting mats, according to Branford fire marshal Shaun Heffernan.
Firefighters held back initially because of the danger of explosions, but emergency crews used a drone to fly over the quarry and send back pictures to determine how close the flames were to the explosives.
Officials determined the explosives were secure and firefighters moved in to fight the flames around 5:15 p.m. People were also allowed to return to their homes.
Shelters had been set up at the Community House at 46 Church Street and Mary T. Murphy School at 14 Brushy Plain Road for residents who were moved from their homes.
The State Police Bomb Squad, members of the State Police Fire & Explosives Investigative Unit, and ATF agents also responded to the scene.