It's every parent's nightmare: a missing child. With every passing hour, the tendency to think the worst grows. CBS News' 48 Hours reports on how parents and authorities responded in three cases. Traci Rene Conrad: On Feb. 25, 1996, Traci, an 11-year-old girl who lived in California's Central Valley, disappeared. Authorities and local people spent the next 25 days searching frantically for the little girl, often slogging their way through pouring rain. Finally, Rene's body was found in a kiln, just a few blocks from the Conrads' house. The kiln belonged to the Galik family, and police soon arrested a former truck driver named Kevin Galik, then 37. When she disappeared, Rene had been on her way to visit Galik's children. She was found wrapped in a sheet matching those inside the Galik home, and a man's T-shirt was wrapped around her head. The shirt was Kevin Galik's size. Galik claimed innocence, but at his trial, prosecutors produced several witnesses who undercut his alibi. He was convicted of murder and sentenced to life in prison without the possibility of parole. Rene's parents, Chris and Terri, have since become vocal advocates for better, quicker police response to child-related crimes. Baby Kerri: In July 1992, Kerri Mammini, who was then 2 days old, was snatched from the Alta Bates Medical Center in San Francisco. Three months later, after a frenzied nationwide search, Kerri was found in the possession of Karen Lea Hughes, a 40-year-old woman. Hughes, who said she had kidnapped the baby to ease her distress about a miscarriage, was sentenced to eight years in prison. Kerri now lives with her mother, Jessica Mammini, in the San Francisco area. Robert Kloack: In 1987, Robert Kloack's mother lost a custody battle for her son. In response, she went underground, taking her 3-year-old son to Florida. She taught him at home and seldom let him go outside. When he was found after five years and returned to his father Tom in Idaho Falls, Idaho