MSNBC Live with Alex Witt 08/30/14

Geological expert: Napa should prepare for next earthquake

Keith Knudsen, deputy director of the U.S. Geological Survey, updates Alex Witt on the 6.0 earthquake that struck Southern California this week and the issues Napa Valley faces as dozens of aftershocks continue to rock Napa Valley. ... more Duration: {{video.duration.momentjs}}