There is a reason for safety rules.

At least 36 people were killed Wednesday when one of South Korea’s worst fires in years broke out at a construction site near the capital, officials said.

They said the death toll could rise because more people were believed to be trapped inside the warehouse that was under construction in Icheon, just south of Seoul.

The blaze erupted early in the afternoon and hundreds of firefighters took several hours to put it out. Images from the scene showed several firetrucks and more than a dozen ambulances surrounding the badly damaged structure, which was completely blackened and writhed on one side. Rescue workers in white protective suits were seen carrying out victims in body bags.

Park Soo-jong, an official from Gyeonggi province fire services, said 25 workers were pronounced dead at hospitals and the bodies of 11 others were being recovered at the site.