At 20:38 hours, Station 50 was dispatched to an Automatic Fire Alarm (AFA) at 240 S Main St in the Borough of Nazareth. Truck 5021 & Engine 5012 arrived shortly after and sent crews in to investigate. 5056 (LT Hyman) reported smoke in the basement, which upgraded the incident to a commercial structure fire. 5021's crew made their way further into the basement and found a Kerosene Forced Air Heater actively on fire from the inside. Crews knocked it down with a water can and kept it contained to the heater.

Due to the size of the building and amount of smoke, Station 53 (Hecktown) was dispatched for their large fan to assist with ventilation.