Metro-North Derailment: What Past Crashes Teach Us

The latest information on yesterday's deadly Metro-North derailment in the Bronx: Richard Hake and Andrea Bernstein of the WNYC newsroom, and The Wall Street Journal's Ted Mann, update what we know about the cause, the investigation, and disruptions to local commuting.  Plus, George Bibel, mechanical engineering professor at the University of North Dakota and the author of Train Wreck: The Forensics of Rail Disasters (Johns Hopkins University Press, 2012), adds more information about derailments and what systems might prevent future such accidents.