At around 1500 hrs units were dispatched for a Plant fire in the lanier industrial park. Once units were in-route dispatch advised that there was a caller on the line advised black smoke was coming from a vent on top of the building. Car 1 (Allen) arrived on scene and advised the same due to the hydrant being 3000 ft away water supply was set up and a tanker shuttle was started. Crews advised the building was full of black smoke and they could see one of the generators inside with fire coming from under it. Due to high voltage crews waited till the power company advised that the power was shut to the complex and entered and extinguished the fire then ventilated the structure. Units-Engine 11,12,31,21 Squad 17 Ladder 5 Tanker 36 26 Car 1 and 3