When a deadly landslide hit Sitka, Alaska in 2015, it sparked conversations about safety and risk. The community has an early warning system for tsunamis. Could it work for landslides? Or would another solution have to be developed? Producer Molly Segal finds out. Then -- with climate change increasing the risk of landslides, we hear how sound waves imperceptible to the human ear can tip us off minutes before the hazard occurs in the Pemberton Valley, north of Whistler, B.C.