Footage of Tropical Storm Hilary's impact on Southern California has been widely shared in recent days — including this eye-opening mudslide that occurred in San Bernardino County. » Sign up for our newsletter KnowThis to get the biggest stories of the day delivered straight to your inbox: go.nowth.is/knowthis_youtube » Subscribe to NowThis: go.nowth.is/News_Subscribe The county's fire department shared this clip on Aug 21. It warned residents about the severity of the storm, writing how the footage 'shows the power of debris flows.' 'They happen fast, and they're unpredictable. When evacuation orders are issued, leave immediately. Property can be replaced. You & your loved ones lives cannot,' the department wrote. For more U.S. news, subscribe to @NowThisNews. #TropicalStormHilary #Hilary #California #Politics #News #NowThis Connect with NowThis » Like us on Facebook: go.nowth.is/News_Facebook » Tweet us on Twitter: go.nowth.is/News_Twitter » Follow u...