Fire crews are responding to a three-alarm fire in northwest suburban Crystal Lake. The fire reportedly broke out in an industrial commercial area on Commercial Road in a building formerly occupied by a manufacturing company called Dimatronics. The roof of the single-story brick building was partially collapsed as of 3:30 p.m. and fire crews were battling flames and plumes of smoke billowing from the roof. The business is located on the southern end of Crystal Lake, near Virginia Road.