Support WBURMigrants Are Stuck In Mexico With Violence Back Home And 'Zero Tolerance' In The U.S.Play08:47Download AudioJames FredrickLulu Garcia-NavarroJune 24, 2018 ShareThe train known as "The Beast" passes by the Sagrada Familia shelter in Apizaco, Mexico. For many migrants, the train is the next step in their journey north. (Alejandro Cegarra for NPR)