This evening, the Squad was dispatched to York County, Carroll Twp for a working building fire. YC units were operating at Livingston Excavating on Blair Mountain Dr where a fire had started in a storage building. First arriving units found explosions occurring and heavy fire. Squad 12 arrived and assisted with extensive overhaul of the building. Squad 12 returned around 1900hrs. One firefighter was injured in a collapse and transported to a local hospital with non life threatening injuries. The fire is under investigation.