The deaths of 50 migrants – traveling from Mexico, Guatemala and Honduras – in terrible conditions in Texas has cast a spotlight on the immense risks people are willing to take to cross the US border in search of a better financial life or escaping violence in their native countries.

Laura Peña, the legal director of the Texas Civil Rights Project, represents asylum seekers at the border. Responding to the tragedy in San Antonio, she said both the Texas governor, Greg Abbott, and President Biden have “utterly failed people who are trying to seek safety by crossing the border”.

“The closure of borders are forcing people to take more dangerous routes. That’s just the facts. It’s resulted in thousands of deaths across the border … And it’s a direct result of these efforts to harden the border and criminalize people instead of investing in processing – simple processing of people who are trying to seek asylum and refuge at our ports of entry at our borders.”

The processes Peña is referring to are the same ones used to allow more than 3,000 Ukrainian refugees to enter the US at the border of Mexico.

She added: “We’ve been advocating for a dignified, humane process at the border, where people are not forced to risk their lives. We’ve seen the ability of the federal government to do that. We saw all the resources come to bear for our Ukrainian brothers and sisters, rapid humane processing at the border. But when it comes to Black and brown migrants, those same benefits are completely stripped away. They are not afforded across the board. It’s the underlying racism, and how and where both the federal and the state governments choose to militarize.”

On Tuesday, Biden called the deaths “horrifying and heartbreaking”.

“While we are still learning all the facts about what happened and the Department of Homeland Security has the lead for the investigation, initial reports are that this tragedy was caused by smugglers or human traffickers who have no regard for the lives they endanger and exploit to make a profit.

“Exploiting vulnerable individuals for profit is shameful, as is political grandstanding around tragedy, and 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.”

The San Antonio fire chief, Charles Hood, said the people found were “hot to the touch”, suffering from heatstroke and heat exhaustion.

The peak of summer in San Antonio, where temperatures remain consistently in the 90s or higher, is no deterrent to those seeking work or fleeing persecution. Nor is the prospect of being discovered by border patrol agents. The result of the treacherous journey, however, is the gruesome image of stacks of bodies.

The number of migrant deaths in 2021 was 650, the most since 2014. The figure is a stark reminder of the human cost of US immigration policies, which generally limit the number of migrants able to seek asylum.

Congressman Joaquín Castro, who represents the district that covers San Antonio, called for ending Title 42, the pandemic-era policy invoked by the Trump administration that allows for turning away migrants without offering them the chance to seek humanitarian protection ostensibly to prevent the spread of contagious diseases like Covid-19.

Castro argued that was an immediate aid to the infrastructure of US immigration, which has been overwhelmed.

More changes to US immigration law are imminent. The conservative-majority supreme court is also set to rule on Trump’s “Remain in Mexico” policy, which forces asylum seekers from Mexico to return home while awaiting the result of their pending immigration cases. Advocates argue the policy makes migrants face a forced return to the unsafe and vulnerable conditions from which they were escaping.

And to avoid that, advocates say, migrants are willing to endure extremely dangerous conditions and risk everything in hopes of making the journey across the US border with Mexico.

Biden tried to end the policy upon taking office, but was unsuccessful.

The American Civil Liberties Union (ACLU) said: “If the supreme court prevents the Biden administration from ending Remain in Mexico, it will enshrine a new legacy for the United States – a legacy of turning its back on international commitments and sending people directly into harm’s way.”

Though Monday’s grim discovery stood among the deadliest tragedies involving migrants, it is not the first of its kind in San Antonio. In 2017, 10 men traveling by tractor-trailer died, having gone without water, food and air conditioning for hours.

Further south in Brooks county, Texas, 10 migrants traveling by van died after crashing into a utility pole last August.

In Houston, six migrants died in an SUV after being chased by police through rainy weather in 2019.

Advocates have long said that those episodes illustrate the risks migrants are willing to take to access the US and leave behind uncertain lives in their native countries.

The Texas senator Ted Cruz and Governor Greg Abbott quickly blamed Biden for the most recent deaths in San Antonio. Abbott said: “These deaths are on Biden. They are a result of his deadly open border policies. They show the deadly consequences of his refusal to enforce the law.”

The condemnation of the president comes after members of the Texas GOP criticized Democrats such as gubernatorial candidate Beto O’Rourke for calling for more meaningful gun control measures after the shooting deaths of 19 children and two of their teachers at a school in Uvalde.

Following news of the dead in San Antonio, O’Rourke echoed calls for expanding avenues for legal migration to discourage human smuggling rings responsible for organizing such dangerous trips across the border.