Chat with us in Facebook Messenger. Find out what's happening in the world as it unfolds.

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)
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)

    JUST WATCHED

    How safe is train travel?

MUST WATCH

How safe is train travel?

CNN's Dan Simon takes a closer look at recent train derailments and whether or not traveling by train is safe.

How safe is train travel?

CNN's Dan Simon takes a closer look at recent train derailments and whether or not traveling by train is safe.