An explosion rocked Ringneck Energy ethanol plant in Onida, South Dakota Sunday causing major structural damage to the facility.

No one was injured at the plant but DRG Media Group reports there were six employees working at the time. “The explosion occurred in the ethanol production side of the plant,” said Onida Volunteer Fire Department Chief Caleb Shepherd. “Major damage to the facility. It will be out of operation for quite some time.”

The South Dakota Fire Marshal’s Office will begin an investigation on Monday.