PITTSBURGH — (WPXI) – Multiple crews battled a large house fire in Pittsburgh’s South Side Slopes neighborhood. According to officials, the fire started around 8 p.m. Sunday on Mt. Oliver Street and quickly engulfed the entire side of the structure. Channel 11 crews could see flames shooting out of the roof and side of the building, and officials said neighboring homes were also evacuated to keep residents safe from potential spread. The fire reached three alarms, and four firefighters were taken to the hospital with non-life-threatening injuries sustained while battling the flames. It’s unclear how the fire started, and safety officials told Channel 11 there were two collapses in the backside of the building. That is where most of the damage is. However, fire officials said two nearby buildings were severely damaged due to water and smoke. Luckily, everyone that was inside the building made it out safely after the fire started.