An employee at an incineration plant in Aalborg sustained critical injuries following an explosion on Wednesday at noon. North Jutland Police confirmed the individual’s condition.

The incident occurred when a valve apparently loosened, resulting in a fireball that struck two employees. The employees were in the process of replacing a pipe when the explosion took place.

Authorities have reported that the second employee present at the time of the explosion suffered less serious injuries.

Nordværk Affaldsenergi explained that the combustion furnace is typically designed to absorb pressure waves resulting from explosions.

The Danish Working Environment Authority has been notified and will conduct a thorough investigation into the circumstances surrounding the accident.