(NewsNation) — Migrants on the move from South and Central America risk it all when they climb aboard freight trains dubbed La Bestia and El Tren de la Muerte — or, in English: “The Beast” and “The Train of Death.”

The trains travel north to the U.S.-Mexico border carrying grains, industrial materials and thousands of people a year who are hoping for a better life in America.

These aren’t passenger trains with comfortable seats and large windows taking in the views of jungles. They’re dangerous freight trains wherein migrants often sleep in coils of metal or atop a bed of rocks. People have been killed under the trains’ crushing wheels; limbs have been lost as well.

José, a migrant from Venezuela, says the risk is worth it.

“All of us who are here are from Venezuela,” he said. “Many migrants are in the same situation. It is difficult and complex. Every time they put more and more obstacles in our way, we will continue to move forward.”

The trek takes anywhere from a few weeks to months, depending on how many times the migrants get off and on looking for food or aid. Some of them are robbed along the way, and some are kidnapped and held for ransom.

The weather is also a hazard. Sitting on top of the train cars, the nights are frigid and the blistering heat often burns the migrants when they touch the scalding metal.

Not much is done to stop the migrants from hopping on the trains.

In some cases, the conductors make money by taking bribes to look the other way. U.S. Customs and Border Protection even created a song to warn of the dangers. “La Bestia Norte” is played on the airwaves in some Central American countries.