The earthquake that struck China’s central region yesterday is the deadliest the country has seen since 1976. We talk with Roger Bilham, professor of geological sciences at the University of Colorado at Boulder, about how both natural and man-made factors created such devastation. Guest: Professor Roger Bilham is an expert in earthquake prediction and the impacts of urban growth on earthquake-related fatalities. His research has taken him to South Asia and China’s Chengdu region.