WOOD RIVER, Neb. — Authorities are releasing more details about the explosion that killed one person and injured four others at a Central Nebraska ethanol plant.

The Nebraska State Fire Marshal Agency says the explosion at Green Plains in Wood River was reported at 2:39 Monday afternoon. Responding firefighters found that a liquid holding tank had been involved in the explosion but there was no fire present.

One Green Plains employee was declared dead at the scene. Another employee remains at an Omaha hospital in critical condition. Three contractors were taken to a local hospital, treated for minor injuries and released. The Hall County attorney has ordered an autopsy for the person who died. The fire marshal is waiting to release the victim’s name pending identification and notification of family.

The fire marshal says the explosion was accidental and a result of work being conducted on the liquid holding tank. It is not related to the fire that happened on Friday at the facility.