GASTONIA, N.C. (QUEEN CITY NEWS) — A blaze along a major thoroughfare in Gastonia shut down traffic most of the day Wednesday while firefighters worked to extinguish the flames. The fire, which was initially reported along the 1300 block of East Ozark Avenue just after 5 a.m., Wednesday, Jan. 22, covered three stories of a vacant building that was reportedly used by the city's homeless. Gastonia Fire Chief Phil Welch told media Wednesday morning that a witness had seen a man go inside the building with a propane tank, shortly before that witness reported hearing an explosion and seeing a man running out of the building. View this post on Instagram A post shared by Queen City News (@fox46charlotte) The building is known to be used by the city's homeless. The fire led to a road closure along East Ozark Avenue, which snarled traffic most of the day. GCOEMFSGCOEMFSGCOEMFSQCN: Smoke seen from I-85QCN: Smoke seen from I-85 Firefighters reopened most lanes to traffic shortly after 3:30 p.m. Wednesday, but still had fire crews on the property of the vacant building. Firefighters noted, that due to the below-freezing temperatures, a number of fire hydrants in the immediate vicinity had issues working as they were preparing to fight the blaze. Welch noted the cause of the fire was, officially, still under investigation, and the witness report regarding the propane tank was being looked into.