Desperate Migrants Risk Dangerous Journeys as Policies Shift

Thousands of poor migrants in Mexico are riding freight trains north to the US border.
The migrants are rushing to reach the border before a policy allowing rapid expulsions ends.
Though uncertain of the new rules, migrants want to reach the border as soon as possible.
The migrants, including families with children, are mainly from Venezuela aiming for Ciudad Juarez and the US.
The journeys expose migrants to dangers from gangs, harsh weather, and accidents.