An accident at the Arkansas Nuclear One plant in Russellville, Ark. claimed the life of one worker and injured three others.

The accident occurred Sunday at 7:45 a.m.. Entergy Corp reports that a generator fell as it was being moved, killing one and injuring three others. There was no nuclear release.

According to Entergy, the incident has been classified as an "unusual event" by the Nuclear Regulatory Commission, which is the lowest of four emergency classifications.