OMAHA, Neb. (AP) – The Defense Department says a 29-year-old Omaha man has been killed in Afghanistan.  Officials said Tuesday that Marine Sgt. Joshua Robinson died Sunday while on combat operations in Helmand Province.  He was shot twice in the left side of his chest while on patrol.  Robinson was on his first deployment to Afghanistan but had been deployed to Iraq twice before.  He enlisted in the Marines in 2003.  Robinson earned a Purple Heart and Combat Action Ribbon during his service.  Robinson was an infantryman assigned to the 1st Battalion, 5th Marine Regiment, 1st Marine Division, which is based at Camp Pendleton, Calif.  Robinson’s wife and two sons, ages 4 and 5, moved back to Bennington, Neb. earlier this year to be close to family while he was deployed.  The number of service members with Nebraska connections killed in Afghanistan or Iraq since September 11, 2001 continues to grow.  The latest U.S. military casualties in Afghanistan bring the total of deaths with Nebraska ties to 70.  The Defense Department said Tuesday that Marine Sgt. Joshua Robinson from Omaha was killed Sunday in Afghanistan during combat operations.  Family members say two other soldiers from Nebraska died Saturday when a military helicopter was shot down in Afghanistan.  Twenty-six-year-old Navy SEAL John Douangdara and 30-year-old Nebraska National Guard Sgt. Patrick Hamburger were among the 30 American troops killed in the crash.  Douangdara is from South Sioux City. Hamburger is a Lincoln native who lived in Grand Island.