Flames engulfed a commercial building at the Lawrence Aviation site on Sheep Pasture Road in Port Jefferson Sunday night.
Port Jefferson Fire Department was originally called to the scene as a smoke investigation but later discovered the fire.
The site, formerly occupied by the aviation company, has been a source of controversy for years, and plans to clean up the brownfield and caused by years of chemical dumping there continue to take shape.
Port Jefferson requested Terryville Fire Department to respond as well since the fire was located in its district. Five other surrounding fire departments were called to the scene including Setauket, Mount Sinai, Miller Place, Selden and Coram.
According to one eyewitness, the "power had gone out a few times just as it (the fire) started."
"While the power was out we saw large flashes of white/blue light in the sky then yellow light and big explosions," the person reported anonymously to Patch by email. "Black smoke was seen rising against the sky. Lots of small explosions and heard that power lines were coming down near the fire."
The eyewitness also said that he saw explosions coming from Lawrence aviation main entrance road as well as deep into the power lines near where Chip-It-All at 366 Sheep Pasture Road brushes up against the property.
At the fire, flames held all firefighting to the exerior and no fire personnel were allowed to enter the structure. The fire department reported that they had to "stop all Long Island Rail Road service near the area" because they had a line stretced across the railroad crossing on Sheep Pasture Road.
Stony Brook also provided one engine to cover Port Jefferson's district. Emergency Medical Services were provided by Port Jefferson Volunteer Ambulance, Terryville EMS and Selden Fire Department on scene.
As of approximatley 10:30 p.m. all fire departments were still operating on scene.