Firefighters returned to the scene of a hazmat situation at a pool supply store on Shotwell Road in Clayton on Wednesday morning.
Because of fire damage and limited indoor camera angles, officials said crews were not able to determine the exact cause of the fire.
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According to the Clayton Fire Department, crews were initially called to a commercial structure fire shortly after 6 p.m. on Tuesday at Baystate Pool Supplies, located at 853 Shotwell Road.
When firefighters arrived, they discovered a substance, sodium hypochlorite, burning in the building. There was light smoke but no visible fire, and crews said there was no threat to the public.
Clayton Fire Chief David Ranes said the fire activated an overhead sprinkler system putting water onto pallets of a common pool chemical product known as "SHOCK."
Ranes said when “SHOCK” gets wet, it produces a chlorine gas, and that is what firefighters found when they arrived.
People in the area may notice the smell Wednesday morning, but it is not harmful, according to officials.
Sky 5 flew over the scene Tuesday evening shortly after the call went out, where smoke was visible coming out through one of the doors of the building.
Fire crews from the Clayton Fire Department, the Cleveland Fire Department and the Garner Fire Department all responded along with Johnston County Emergency Services and Johnston County Emergency Management.
Air monitoring was conducted at the scene, and firefighters allowed fresh air to circulate. As a precaution, the building and nearby businesses were evacuated.
According to a company spokesperson, no employees were on scene at the time of the call and no injuries were reported.