February, 1959. Nine young hikers set out into the Siberian wilderness for a few weeks of outdoor fun...and fell victim to a horrific tragedy that took on legendary status and remained unresolved for decades. Now, stunning new evidence has reopened the bizarre case of the Dyatlov Pass incident. Investigators wonder: were these nine hikers slaughtered by a Yeti? Watch #YetiMassacre, a 2-hour special investigation, tonight at 9p on Discovery.