The state Fire Marshal's office said Monday the grain elevator explosion at Sedan was an accident.
Spokesman Ray Nance declined to provide any more details about what caused the accident because of the ongoing investigation.
An employee of the Aurora Cooperative and a farmer who was delivering grain were injured in the blast, which happened at about 4:30 p.m. Friday.
They were taken to Fillmore County Hospital in Geneva before being flown to a hospital in Lincoln. No information on their identities or conditions was available.
Dawn Caldwell, a spokesperson for the co-op, said the families of the two people injured are not commenting on their conditions at this time.
Sedan is an unincorporated area between Edgar and Davenport on the Union Pacific rail line in Nuckolls County.
Fire departments from Edgar, Davenport, Sutton, Shickley, Superior, Fairfield and Clay Center responded to the scene.