National Transportation Safety Board (NTSB) Chair Deborah Hersman, center, presides over a NTSB meeting in Washington Tuesday, July 10, 2012, to determine a cause of a pipeline rupture

 

              National Transportation Safety Board (NTSB) Chair Deborah Hersman, center, presides over a NTSB meeting in Washington Tuesday, July 10, 2012, to determine a cause of a pipeline rupture
National Transportation Safety Board (NTSB) Chair Deborah Hersman, center, presides over a NTSB meeting in Washington Tuesday, July 10, 2012, to determine a cause of a pipeline rupture in 2010 that dumped more than 800,000 gallons of oil into a southwestern Michigan river. . (AP Photo/Manuel Balce Ceneta)