The HFCo.#1 was alerted for an odor of Natural Gas inside the structure. Engine / Rescue 5312 responded with staffing of 5. 5353 (Assistant Chief Hinkel) arrived on the scene, meeting management in the parking lot, and established 53 command. 5312 arrived and sent crews with air monitors to the theaters with the odor. Problem was found, and the odor dissipated.