>> reporter: april 1st, 2011. dawn in denver, colorado. bright, springlike. and for the friends of 19-year-old kenia monge, terrifying. >> i just kept calling her and calling her. we were all worried and scared. >> reporter: where was she? kenia was supposed to have met her friends at a downtown bar the night before. didn't show. and now she didn't answer her phone. not like kenia. not at all. >> we didn't know what happened. nobody knew nothing. >> reporter: kenia's friends truly frightened now kept texting and calling. but not a single lead turned up. no tips, no clues and no kenia. >> we were just trying to be strong because we don't want to