A day on the lake with friends turned tragic Saturday after a Nashville man drowned while swimming at the Sandbar area of Rock Island State Park.The man, Adrian Joel Alvarez Moreno, 26, went under the surface and never came back up as he and several others were swimming in the fairly calm waters of the popular swimming hole.The incident happened Saturday afternoon about 30 feet away from the sandy shore where numerous people were enjoying relief on the muggy day. Witnesses say Moreno and friends were swimming from the Sandbar to the cliff face across the lake and were making their return trip when the victim started struggling and went under. Park officials caution against making the swim since it is a deceptively long swim.Park officials and Rescue Squad members began searching the immediate area where the victim was last seen.