Georgia authorities are investigating an explosion at power plant 50 miles north of Atlanta.
Four plant employee suffered a minor injuries and all others are accounted for, according a spokesperson for Georgia Power, owner of the plant. Only one of the four injured was sent to the hospital, and has been released.
The explosion occurred as the plant was preparing for a planned maintenance outage at the Plant Bowen Unit 2, a coal-fired power plant near Euharlee, Ga.
Witnesses told NBC Atlanta affiliate WXIA the explosion sounded "louder than a sonic boom."
There have been no injuries reported to residents around the plant.