Fire districts 17, 16 & 12 were dispatched to a reported structure fire at the Comfort Inn on Route 940 Saturday night. Ladder 17 arrived on scene with a smoke condition on the 6th floor. A window HVAC unit had caught on fire and filled the 6th floor with smoke. Crews took out the window in the fire room as well as the window at the end of the hallway in order to ventilate the hotel. Guests at the hotel knocked down the fire using a fire extinguisher before fire units arrived.