At approximately 9:35 this morning, Engine 4 and Tower 4 were dispatched along with Engine 200 and Engine 5 to assist Station 3 on a dwelling fire. Crews arrived to find an active chimney fire and worked together to extinguish it. Fortunately the fire did not spread beyond the chimney and there was no damage to the residence. While crews were still operating at this call, an additional emergency was occurring at the Gulf gas station on Old York Rd near Church Rd. Engine 4 was directed by Chief 3 to respond and assist Engine 5 for the report of a gasoline tanker on fire next to the gas pumps. The fire was contained to the rear brakes of the tanker and quickly controlled. We thanked the driver for quickly reacting and notifying 911. This incident had the potential to be far more significant and dangerous.