A 31-year-old Campbell man drowned last Saturday while swimming in Lake Tulloch in Calaveras County, according to officials. The man reportedly swam from the lake’s main shoreline to an island roughly 90 feet offshore, the sheriff’s office said. As he was swimming back, he became fatigued and started to struggle. He disappeared under the surface and did not come back up. He was not wearing a personal floatation device. Sheriff’s deputies respond…