DECATUR BOY RESCUES LITTLE SISTER Thursday, February 19, 2004 cmccool@kalamazoogazette.com 388-8575 DECATUR -- The ground opened up and swallowed his little sister, and Vaughn Copeland jumped in after her. Some people grow old wondering whether they'd make the right split-second decision in a crisis. At the age of 7, Vaughn proved himself a hero. He saved his little sister's life Monday. The siblings were playing outside in the family's back yard Monday night when an abandoned septic tank suddenly collapsed beneath Alexanna Copeland. The 4-year-old girl fell into a cavity filled with water well over her head. "She knows how...