Los Angeles County's Annenberg Wildlife Crossing is a  90-million-dollar bridge now under construction. It's designed to connect green spaces between a freeway so animals can cross safely. But animals don’t need these kinds of crossings to be so expensive and fancy. There are smaller and cheaper ways to cross the road. Guest: Seth Riley, Biologist, National Park Service Some of the country’s cities, including parts of San Francisco, are slowly sinking, according to a new study. But in San Francisco, tectonic activity and areas built on reclaimed land are causing the subsidence. Reporter: Ezra David Romero, KQED Learn more about your ad choices. Visit megaphone.fm/adchoices