Firefighters were called to Magnetic Metals in Camden's Cramer Hill neighborhood at around 10:50 p.m. Monday as the fire raged through the complex.
Neighboring fire departments also provided assistance as the fire continued to burn overnight.
There were no reports of injuries.
Magnetic Metals is one of the last remaining active manufacturing plants in Camden. The company, founded in 1942, specializes in stamped metal products used in a number of industries, including defense contracting.
There is no word yet on a cause.
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