The fire was suspected to have started during welding work in the basement of the building in Goyang city, just north of Seoul, said Ha Jong-keun, an official at an emergency office in Gyeonggi Province which governs the city.
The terminal building also has a multiplex movie theatre and a shopping mall, but witnesses told local media that not many people were at the scene at the time of the fire, reported about 9 am. Ha said the fire was put out in 20 minutes.
Emergency officials earlier said seven people died but corrected the toll to six. The misinformation was provided because one of those seriously injured was assumed to be dead but was resuscitated with CPR, said officials who requested anonymity citing department rules.
Ha said officials haven't identified the six dead people except that three are men and three are women. He said at least five of them were found on the second floor of the building.