The Kenilworth Fire Department and Rescue Squad responded to New Jersey Mirror and Glass on the 700 block of Kenilworth Boulevard around 3:25 a.m., the rescue department said.
Smoke and flames were shooting out of the building, and a second alarm was called. Fire departments responded for mutual aid and firefighters went into the burning building, but left soon after — just before the roof collapsed.
Defensive tactics shifted to the exterior of the building, and a third-alarm was called.
After nearly three hours, the fire was place under control. The Kenilworth Rescue Squad established Fire Rehab and assessed all firefighters on scene and provided them rehabilitation.
The Union Fire Department, Cranford Fire Department, Roselle Park Fire Department, Scotch Plains Fire Department, Springfield Fire Department, Garwood Fire Department, Union County EMS, and Kenilworth Police Department responded.
Mountainside Fire Department, Fanwood Fire Department, and Clark Fire Department provided town coverage.
The blaze remains under investigation.
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