Sprinklers held a fire in check Thursday night at an apartment building until firefighters could knock it out.
At about 9 p.m. Upper Darby stations 36 and 37 were dispatched to 6800 Market St. for a fire alarm.
Crews arrived to find residents evacuating the building and fire and smoke on the fourth floor.
Firefighters from Truck 37 went to that location and found heavy smoke and water coming from an apartment as firefighters from Engine 36 began the process of bringing a hose line up the fire tower.
The confirmed working fire brought remaining township companies to the scene as well as additional units, including a platform truck from Llanerch Fire Company.
Upper Darby Professional Firefighters Union said in a social media post that an active fire was located, being held in-check by the building sprinklers, but needing further extinguishment and ventilation from crews.
Interior crews quickly extinguished the remaining fire and searched the apartments.
No injuries were reported and the cause of the fire is under investigation by township investigators.