to safety. we set up sandbags over the weekend thinking that would be sufficient. but it blew right through them. reporter: as a once in a lifetime tropical storm flooded cities, mountains, and deserts, collapsing summer records across the entire region. there s a lot of destruction, right? and mother nature clearly put her mark on us over the last 48 hours. reporter: hilary made land landfall as a tropical storm in mexico, slamming into the baja peninsula. california braced for impact, the first tropical storm to arrive in 84 years. we re not built for this kind of rainfall. that s my main concern. reporter: in one day, san diego got ten times more rain than what it typically sees all summer. and across the region, roads began to buckle. as hilary moved northwest into nevada, the destruction