Three children were killed Wednesday by accidental electrocutions at lakes in Missouri and Tennessee, authorities said. In Missouri, a brother and sister died after receiving a shock while they were swimming in Lake of the Ozarks, the Columbia Missourian reported. Alexandra Anderson, 13, and her brother, Brayden, 8, were pronounced dead at Lake Regional Hospital in Osage Beach. The siblings were both from Ashland, Mo., about 60 miles away. Sgt. Paul Reinsch of the State Highway Patrol said the children were apparently shocked by faulty wiring on a dock. He said investigators were trying to determine the exact nature of the problem. At Cherokee Lake in Tennessee, two boys received serious shocks either in the water or from touching a metal ladder on the side of a houseboat, the Knoxville News Sentinel reported. A 10-year-old died but paramedics were able to revive his 11-year-old companion, Grainger County Sheriff Scott Layel said. The shock was believed to have come from the bottom of a houseboat. A girl who was also in the water was injured.