The call to the Testrite plant on South Newman Street came in at 8:17 a.m. after the fire broke out in a malfunctioning dust-collecting machine, city firefighters said.
The sprinkler system knocked down the main body of the blaze, they said.
Firefighters evacuated the building, then vented it after dousing the flames.
EMS evaluated a worker at the scene.
Testrite has been in business a little over 100 years.
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