Campaigners have slammed U.S. politicians following the grisly discovery of 51 dead asylum seekers and at least a dozen others who required hospital treatment after being found inside an abandoned trailer on a remote road in San Antonia, Texas on Monday. 

The deceased include 39 men and 12 women while four minors were among those needing hospital treatment for heat stroke and exhaustion.

At least 27 Mexicans, three Guatemalans, and four Hondurans are believed to be among the dead, according to politicians from all three countries. 

Officials from both sides of the border are working to identify the nationalities of the remaining refugees that were found dead.

According to local and federal officials briefed on an investigation, the truck may have been carrying around 100 asylum seekers, but the exact number remains unclear. The vehicle had been left parked beside railroad tracks as temperatures soared to as high as 40 degrees celsius. 

Reports have cited San Antonio's police chief as saying an individual working in a nearby building went outside to check after hearing a cry for help, found the trailer door partially open, and saw bodies inside.

Speaking to reporters, fire chief Charles Hood said those transferred to the hospital were hot to touch and dehydrated while there was no water or air conditioning system found in the trailer. “We’re not supposed to open up a truck and see stacks of bodies in there,” Hood said. “None of us come to work imagining that.”

The discovery is the deadliest tragedy among the thousands of refugees who have died trying to cross the U.S. southern border from Mexico over the past several decades. 

Politicians especially Texas Governor Greg Abbott and U.S. President Joe Biden have been quick to exchange blame for the deadly incident.

Laura Pena, the Director of Beyond Borders program at Texas Civil Rights Project, has accused both political leaders of being at fault and having "utterly failed" the dead refugees. 

She says President Biden's continued implementation of his predecessor Donald Trump’s immigration policies including - Title 42 - which allows officials at the border to block the path of asylum seekers because of the COVID-19 pandemic is to blame. Also Abbott's “Operation Lone Star”, an initiative that ordered National Guard Forces to be stationed at the southern border is to blame.

The activist says both policies have made the circumstances more dangerous for refugees seeking to enter the U.S. Pena says "when migrants can't cross ports of entry they're forced to take more dangerous routes. 

"This leads to what happened in San Antonio where people's only option is to be locked in a trailer...  as if they're not even human, instead of receiving a dignified, humane process at the border."

"[Biden and Abbot] have utterly failed people who are seeking 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,” she noted, “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 simple processing of asylum seekers that Pena was referring to is being enjoyed by the more than 3,000 Ukrainian refugees allowed to enter the same U.S. southern border with Mexico and allowed to be granted asylum. 

“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,” Pena said. 

She also pointed out that "If putting your life, not just as risk, but affirmatively packing yourself into a container is a better option than remaining in a dangerous situation in which you are currently in, it really speaks volumes of those situations,"

Spokespeople for Biden and Abbott have not immediately responded to requests for comment.

Other campaigners also saw a direct link between the disaster and the Biden administration’s border policies. Aaron Reichlin-Melnick, policy director at the American Immigration Council, said he had been dreading such a tragedy for months. “With the border shut as tightly as it is today for migrants… people have been pushed into more and more dangerous routes. Truck smuggling is a way up,” he wrote on social media.

The San Antonio-based Refugee and Immigrant Center for Education and Legal Services provides legal assistance to those seeking asylum in the U.S.; Miriam Camero, the organization's Vice President of social programs, says the lives lost are a result of a "failure at all levels."

"They clearly lack a moral compass and they use every opportunity to amplify the complete wrong agenda and education for our community," she said of the politicians' response.

"These are not numbers, these are not headlines, these are actually human beings that were trying to seek a better life in the United States," Camero said.

According to Camero, the Refugee and Immigrant Center for Education and Legal Services dispatched attorneys to the scene, where bodies were being recovered and survivors sent for medical assistance, but they were unable to make contact with any of those who survived.

"We will not stop until we get to access and we're able to at least show what options and resources and support these victims do have as well as their family members," Camero declared.

A memorial vigil honoring those lost in Monday's incident has also been held. Jessica Azua, a community organizer, told the crowd "I'm so tired that we have been here before, that we have done this before. It shouldn't be this way," Last year, the number of refugee deaths was 650, the highest annual death toll since 2014. 

The number is a shocking reminder of the human costs because of U.S. immigration policies, which strictly limit the number of refugees able to seek asylum despite being allowed to seek asylum at the point of the refugees’ destination being a right enshrined in international law.

Advocates say because of that; refugees have resorted to extremely dangerous conditions and risk their lives in the hope of making the journey across the U.S. border with Mexico.

The American Civil Liberties Union (ACLU) has warned that unless immigration policy changes are made “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.”

Despite Monday’s disturbing discovery being the deadliest tragedy involving refugees, it is not the first of its kind in San Antonio. In 2017, ten people traveling by tractor-trailer died after going without water, food, or fresh air.

Also in Texas last year, ten refugees traveling by van died after crashing into a pole. In Houston, six migrants died in an SUV after being chased by police through rainy weather in 2019.

Advocates have long said that those cases are an example of the risks and dangers that refugees are being forced to take to seek asylum in the United States.