In this Dateline classic, friends and family of Debbie Hawk are left searching for answers when she vanishes. Investigators discover Debbie had planned to reveal secrets and wondered if silencing her was a motive for murder. Keith Morrison reports. Originally aired on NBC on July 19, 2010. Hosted by Simplecast, an AdsWizz company. See pcm.adswizz.com for information about our collection and use of personal data for advertising.