A dam holding back billions of gallons of water fails and hundreds of lives are lost in the deluge that follows in California. No, it is not a hypothetical "what if?" scenario for the Oroville Dam. It really happened, in Southern California in 1928. Find out the lessons learned and lingering questions about the deadliest man-made disaster of the 20th Century. We speak with the author of Floodpath, Jon Wilkman.