An unknown substance was contained after it leaked from a building in Birmingham. Birmingham Fire and Rescue Service crews responded to the 100 block of 19th Street Ensley just after 5 p.m. today. Battalion Chief Sebastian Carrillo says a container's pop-off valve opened and some substance leaked. HAZMAT and DECON units were able to contain the leak and placed the drum containing the substance into a larger drum. There was no threat to the public. Tests will be conducted to identify the substance.