Explosion at Army ammunition plant in USA

An explosion Tuesday at a sprawling ammunition plant near Kansas City, Missouri, killed one worker and injured four others, the U.S. Army said.

The blast happened at the Lake City Army Ammunition Plant in Independence, just east of Kansas City. Army officials said the explosion occurred in a building where chemicals are mixed and that it has been secured and rendered safe, allowing investigators to begin looking into what caused the blast. The Bureau of Alcohol, Tobacco, Firearms and Explosives will lead the investigation.

All the nearly 1,800 employees at the plant were sent home Tuesday after the explosion and were told to call in before returning to work Wednesday. The four injured workers were evaluated at the scene and declined additional treatment, officials said.

The plant has faced problems in the past. In 2011, six people were injured in an explosion there. Alliant Techsystems, or ATK, was the contractor operating the plant at the time.