FORT STEWART, Ga. (AP) — Officials say an Army sergeant opened fire at Fort Stewart, shooting five soldiers and prompting a brief lockdown at one the country’s largest Army bases. Few details were immediately available about what led to Wednesday’s gunfire. A U.S. official says the shooter is an Army sergeant. The official was not authorized to publicly discuss details of the investigation and spoke to The Associated Press on condition of anonymity. This latest act of violence on a U.S. military installation again raised concerns about safety and security within the armed forces’ own walls.