PHILADELPHIA, PA - MAY 13: Investigators and first responders work near the wreckage of Amtrak Northeast Regional Train 188, from Washington to New York, that derailed yesterday May 13, 2015 in north Philadelphia, Pennsylvania. At least six people were killed and more than 200 others were injured in the crash. (Photo by Win McNamee/Getty Images)
Win McNamee/Getty Images
PHILADELPHIA, PA - MAY 13: Investigators and first responders work near the wreckage of Amtrak Northeast Regional Train 188, from Washington to New York, that derailed yesterday May 13, 2015 in north Philadelphia, Pennsylvania. At least six people were killed and more than 200 others were injured in the crash. (Photo by Win McNamee/Getty Images)
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Caption:PHILADELPHIA, PA - MAY 13: Repair crews inspect damages at the site of a train derailment accident May 13, 2015 in Philadelphia, Pennsylvania. Service has been interrupted after an Amtrak train derailed in Philadelphia last night, killing at least seven people and injured more than 200. (Photo by Alex Wong/Getty Images)
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Caption:PHILADELPHIA, PA - MAY 13: Repair crews inspect damages at the site of a train derailment accident May 13, 2015 in Philadelphia, Pennsylvania. Service has been interrupted after an Amtrak train derailed in Philadelphia last night, killing at least seven people and injured more than 200. (Photo by Alex Wong/Getty Images)
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PHILADELPHIA, PA - MAY 13: Investigators and first responders work near the wreckage of Amtrak Northeast Regional Train 188, from Washington to New York, that derailed yesterday May 13, 2015 in north Philadelphia, Pennsylvania. At least six people were killed and more than 200 others were injured in the crash. (Photo by Win McNamee/Getty Images)
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PHILADELPHIA, PA - MAY 13: Investigators and first responders work near the wreckage of Amtrak Northeast Regional Train 188, from Washington to New York, that derailed yesterday May 13, 2015 in north Philadelphia, Pennsylvania. At least six people were killed and more than 200 others were injured in the crash. (Photo by Win McNamee/Getty Images)
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PHILADELPHIA, PA - MAY 13: Investigators and first responders work near the wreckage of Amtrak Northeast Regional Train 188, from Washington to New York, that derailed yesterday May 13, 2015 in north Philadelphia, Pennsylvania. At least six people were killed and more than 200 others were injured in the crash. (Photo by Win McNamee/Getty Images)
Win McNamee/Getty Images
PHILADELPHIA, PA - MAY 13: Investigators and first responders work near the wreckage of Amtrak Northeast Regional Train 188, from Washington to New York, that derailed yesterday May 13, 2015 in north Philadelphia, Pennsylvania. At least six people were killed and more than 200 others were injured in the crash. (Photo by Win McNamee/Getty Images)
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PHILADELPHIA, PA - MAY 13:  Investigators and first responders work near the wreckage of an Amtrak passenger train carrying more than 200 passengers from Washington, DC to New York that derailed late last night May 13, 2015 in north Philadelphia, Pennsylvania. At least five people were killed and more than 50 others were injured in the crash.  (Photo by Win McNamee/Getty Images)
Win McNamee/Getty Images
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