Alcoa has marked the final day of aluminum manufacturing at its Warrick County plant along the Ohio River in Indiana.
The location had been operating since 1960. The smelter makes alumina, which is a raw material used in the production of aluminum.
The plant, east of Evansville, was one of the largest aluminum smelting facilities in the world.
The company announced in January it would permanently close its Warrick Operations smelter by the end of March. Company officials noted at the time the smelter was not competitive because of a drop in aluminum prices.
About 600 people worked at the smelter. Alcoa has said that about 325 employees will be laid off. The other workers either found new jobs or accepted severance or retirement packages, the Evansville Courier and Press reported. On Thursday, smelter workers took a group photo to mark the shutdown.
The plant's rolling mill and power plant will continue operations. About 1,200 people work at those facilities.