A large structure collapsed at a thermal power plant in the southeastern city of Ulsan on Thursday, and seven people are believed to be still trapped underneath.

According to fire authorities, a 60-meter-high boiler tower at the plant managed by the Ulsan branch of the state-run Korea East-West Power Company collapsed at around 2:07 p.m.

The structure was reportedly facing demolition.

Two individuals have already been rescued from the rubble, while two others have been located and are in the process of being rescued. Rescue teams are working on locating the remaining five workers.

Authorities have deployed three pumper trucks, ten other pieces of equipment, and approximately 50 personnel for the search-and-rescue operation.

Prime Minister Kim Min-seok instructed authorities to mobilize all available resources to rescue those still in danger.