A Twentynine Palms Marine died in combat in Afghanistan over the weekend. The Defense Department announced Tuesday Lance Cpl. Niall Coti-Sears, 23, of Arlington, Virginia, died Saturday while conducting combat operations in Helmand province. Coti-Sears was a rifleman assigned to 1st Battalion, 7th Marines, 1st Marine Division, I Marine Expeditionary Force, Twentynine Palms. Coti-Sears enlisted in December 2008 and was on his first deployment to Afghanistan.