haruki yamaguchi recorded toshiko tanaka's accounts of her experience. tell her story in an app at the locations that were bombed. toshiko: if i look at things in a sober fashion, my time on earth is very limited at this point. i won't be able to tell my story much longer. but this is one way that i can. reporter: many people can no longer tell their story, so toshiko tanaka does it for them. that's her contribution to peace. host: water is our planet's most valuable resource. shortages can be fatal -- we people, for example, can't survive more than three days without water. but pollution, waste, and depletion of natural resources are causing water scarcity, a situation made worse by climate change and population growth. two billion people worldwide have no access to clean drinking water. the u.s. state of california is partly solving its supply problems by recycling. reporter: with historically heavy snowfall and rain since the end of last year, the outlook for california's water supply has drastically changed. but experts agree, it is far too early to