ARKANSAS CITY, Kan. – Officials investigating a fire at Creekstone Farms beef-processing plant are facing delays to start their inquiry due to high ammonia levels. The cause of the fire is under investigation, but it began on a conveyor belt, according to news reports.

The fire started during the afternoon of Sept. 25, according to local news reports. Firefighters believed the fire was under control, but conditions inside the plant made it difficult to investigate. Fire crews stayed outside the building to allow ammonia and natural gas to ventilate. One firefighter was treated for ammonia exposure. He was released the same day. No one else was injured, according to local news reports.

Most of the employees at the plant had Sept. 26 off, while management, shipping and maintenance crews reported to work.