EL PASO, Texas (Border Report) – Deadly falls from the border wall, bodies found in the desert, canal drownings and now, 50 people dead inside a trailer in San Antonio.

The mounting toll of migrants dying in transit to jobs and family members in the interior of the United States is prompting advocates and lawmakers to call for expanding legal pathways into the country and a crackdown on smugglers who put thousands in danger every day.

Late Monday, authorities in San Antonio converged on a remote back road in the southeast portion of the city where a municipal worker alerted them to a body on the ground and others in the back of a trailer, The Associated Press reported. Authorities believe the dead and 16 rescued alive and taken to hospitals with heat-related illnesses are migrants.

Further details are pending, but immigrant advocates say the incident illustrates how federal deterrence policies are forcing migrants to have to risk their lives to come into the U.S.

“This is a serious tragedy caused by the deterrence policies on the U.S.-Mexico border, applied by the federal and the Texas governments,” said Fernando Garcia, executive director of the Border Network for Human Rights. “Title 42, MPP, the border wall and Gov. Abbott’s Operation Lone Star are clearly responsible for this catastrophic human rights crisis.”

International aid organizations say at least 600 migrants died last year while attempting to cross the U.S. border (some died on the Mexican side, the bodies of others haven’t been recovered), but Garcia said the figure is closer to more than 1,000.

“This is an unsustainable situation. We demand immediate action to prevent more unnecessary deaths and immigration border policy solutions that save lives, not lead people to their death.”

U.S. Rep. Veronica Escobar, D-Texas, who has coauthored immigration reform legislation and is spearheading the creation of processing centers that minimize the time migrants spend in federal immigration custody, agreed there’s a need to expand legal pathways to safe and humane immigration.

“How many more deaths will it take to make clear Title 42 and MPP do nothing to deter or end migration, and instead put already desperate people in increasingly dangerous positions?” Escobar said. “My heart breaks for the victims’ families. It’s on Congress to act to stop the next tragedy.”

Title 42 is a public health order that lets immigration officials immediately expel non-citizens without proper documents to be in the country. MPP is the “Remain in Mexico” program forcing asylum seekers to wait across the border to be called to asylum hearings in the U.S.

But disempowering human trafficking organizations should be a top priority, said U.S. Rep. Tony Gonzales, R-Texas, whose district stretches from Northeast and Far East El Paso to San Antonio.

The death of the 50 migrants “is yet another example of the ruthlessness that human smugglers display as they seek to profit off their victims. Unfortunately, situations like these are common along the Texas border and will likely continue until enforcement efforts against criminal operations are scaled up,” Gonzales said.

He called on “disincentivizing” the transnational criminal organizations that control the illegal passage and transportation of migrants at the U.S.-Mexico border.

“We’re on a path to exceed record-breaking numbers of migrant deaths and rescues,” he said. “This is the devastating reality of the crisis at our southern border. Current open-border policies are anything but compassionate. Instead, they have encouraged hundreds of thousands of migrants to rely on a ruthless smuggling industry run by cartels.”

According to the latest figures from the Department of Homeland Security, border agents and port of entry officers encountered 239,416 unauthorized migrants at the Southwest border just in May. That brings the total to 1,536,899 encounters on the Southwest border since October 1, and 1.75 million encounters nationwide.

President Biden on Tuesday morning commented on the imperative to crack down on smuggling organizations. But he also asked that people refrain from using the tragedy for political grandstanding.

“This incident underscores the need to go after the multi-billion dollar criminal smuggling industry preying on migrants and leading to far too many innocent deaths,” the president said. “My Administration will continue to do everything possible to stop human smugglers and traffickers from taking advantage of people who are seeking to enter the United States between ports of entry.”