A conveyor belt was undergoing welding work when fire broke out Thursday afternoon at a four-story ready-mix cement factory in Busan, South Korea.
At about 3:27 p.m. flames were first reported. The welding being done on the second floor somehow spread through the upper floors of the steel sandwich panel structure.
Nine workers quickly evacuated the scene. Two workers conducting the welding inhaled smoke but required no treatment.
Firefighters extinguished the flames shortly after 5 p.m.