Yesterday morning the Hinsdale FD was alerted for a possible fire in a commercial building. Several callers were advising they had heavy black smoke coming from the roof and had smoke in the buildin. The box called for Liverpool, C3 (D/C Manley), C4 (D/C Lafaver), and E1 (Capt Warren) responded. C3 arrived and assumed command with smoke showing while E1 was second arriving, taking a position in the rear to gain access to the rooftop. The crew was able to quickly get to the roof, finding a fire in an HVAC unit. 1 line was stretched from E1 and the fire was extinguished with minimal extension. Crews were picked up and release within an hour.