At least 50 migrants found dead in semi - Lanzhou Celestial Spark Group

Emergency personnel surveyed the scene where 46 immigrants were found dead in a tractor trailer on the Southwest Side.

Forty-six immigrants were found dead Monday night in a tractor trailer on a stretch of scrubland on the Southwest Side.

Four more people who were discovered still alive in the rig have since died, bringing the death toll to 50, Mexican Foreign Minister Marcelo Ebrard said Tuesday morning.

The dead include 22 immigrants from Mexico, seven from Guatemala and two from Honduras, Ebard said in a Tweet. The rest are still being identified.

The new deaths come after law enforcement officials found nearly 100 people inside a tractor trailer on Quintana Road near Lackland Air Force Base — a desolate area marred by illegally dumped trash and wrecked furniture, with at least one salvage yard close by. Forty-six were pronounced dead at the scene.

Human smugglers favor largely unpopulated areas like that section of Quintana Road to drop off immigrants. San Antonio, with Interstate 10 running east to west and Interstate 35 south to north, is a major crossroads for human smuggling.

Emergency personnel transported 16 people to area hospitals for treatment — 12 adults and four pediatric patients, who were likely teenagers. Hood said the patients they treated at the scene — men and women — were "hot to the touch."

At least five of the patients remained in critical condition on Tuesday, local hospital officials said.

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San Antonio Mayor Ron Nirenberg speaks about the tragedy at the scene where 46 people have died in a semi-trailer at Quintana Road and Cassin in San Antonio on Monday, June 27, 2022.

Councilwoman Adriana Rocha Garcia shows concern as she explains in Spanish the situation where as many as 46 people have died in a semi-trailer of at Quintana Road and Cassin in San Antonio on Monday, June 27, 2022.

Franciscan priests Father Serafil Bdeho, right, Father Donald Rank and Father Rajau Jeron pray and offer support at the scene where 46 people were found dead in a tractor trailer near Quintana Road and Cassin Drive.

Emergency personnel surveyed the scene where 46 immigrants were found dead in a tractor trailer on the Southwest Side.

People gather near railroad tracks where 46 immigrants were found dead inside a tractor trailer on San Antonio's Southwest Side.

Many of the survivors were suffering from heat stroke and heat exhaustion, San Antonio Fire Chief Charles Hood said. There were no signs of water in the truck.

Temperatures in San Antonio hovered close to 100 degrees Monday. Hood said the back of the rig was refrigerated, but no air-conditioning unit was visible when emergency personnel entered.

Many of the people found inside the truck were covered in steak seasoning, one law enforcement official said Tuesday, likely in an effort to disguise their scent as the smugglers were transporting them.

Timothy Tubbs, who retired as the deputy special agent in charge of Homeland Security Investigations in Laredo, said smugglers commonly use seasonings and other substances to aid their smuggling operations.

There are about 46 migrants dead in San Antonio. Our prayers raised up to you O Lord for their souls. Lord have mercy on them. They hoped for a better life. Lord after Uvalde and now this, help us! We need you! So many people suffering. God, God, God.

"Dogs are trained for several things. Some are trained to smell money. Some are trained to smell narcotics, weapons, and some dogs are trained to smell human beings," Tubbs said. "They will put seasoning on them to cover their scent so they can get through the Border Patrol checkpoint."

Police Chief William McManus said three people were in custody, but he declined to elaborate. Homeland Security Investigations agents are now spearheading the investigation.

"HSI San Antonio has initiated an investigation with support from SAPD," the federal agency said in a written statement. "The criminal investigation remains ongoing."

This is devastating. Our thoughts go out to the families of those who lost their lives in San Antonio today. We need urgent action — dismantle human smuggling rings and replace them with expanded avenues for legal migration that reflect our values and meet our country's needs. https://t.co/FVDBGFm9Oh

Meanwhile, the San Antonio Police Department, in coordination with HSI, redeployed K-9 dogs Tuesday morning near Quintana Road in an effort to find any potential victims that may have fled the tractor-trailer before first responders arrived.

Law enforcement officials feared some migrants could have fled the scene and died in the surrounding areas.

Alex Selgado of Fuerza Catracha, a Honduran immigrants organization in the U.S., said at the scene that "officials did inform us that some of the deceased may be Honduran because they had emblems or insignia of our country" on their clothing.

Marcelo Ebrard, Mexico's foreign minister, said on Twitter late Monday that two of the 16 survivors transported to San Antonio hospitals were Guatemalans.

The news of the deaths drew an outcry from immigration advocates.

"We are devastated by the news," said Cesar Espinosa, an immigrant advocate with FIEL Houston, an immigrant rights organization. "Unfortunately this is not the first time and unfortunately it won't be the last time that it happens as long as we don't have a pathway for people to migrate safely into the U.S."

Border officials have reported a record number of migrant arrests at the U.S.-Mexico border in 2022, as Central Americans and people from around the world arrive there, often fleeing violence and poverty, in part due to worsening conditions after the COVID-19 pandemic.

McManus said police were first called to the scene around 5:50 p.m. after nearby workers heard cries for help and walked over to the tractor trailer to investigate.

One person was outside the trailer laying on the ground, Hood said. The workers opened the doors and discovered the dozens of dead, McManus said.

Hood said they were "too weak to get out and help themselves," adding that it wasn't clear how long they had been inside the tractor 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."

Hood said paramedics used a 12-lead ECG, a standard tool EMTS use to screen patients for cardiac activity, but that no such activity was found among the 46 dead.

Hood said all the patients that they transported were "conscious and alert."

Patti Tanner, director of public relations at Baptist Health System, said that the Baptist Medical Center downtown received five patients. As of Tuesday morning, two had died; three remained in critical condition.

Emergency personnel surveyed the scene where 46 immigrants were found dead in a tractor trailer on the Southwest Side.

Elizabeth Allen, a spokeswoman for University Hospital, said the hospital had received two patients from the scene. Early Tuesday, a 23-year-old woman remained in serious condition, and an adolescent male was in critical condition.

Cheri Love-Moceri, a spokesperson for Methodist Healthcare System, said that Methodist Hospital Metropolitan had received three adult patients, all in stable condition.

Two patients — a 26-year-old woman and 32-year-old man — were transported to Texas Vista, formerly known as Southwest General Hospital, a spokeswoman said. Both were in critical but stable condition early Tuesday morning.

Mayor Ron Nirenberg described the event as "tragic."

"There are, that we know of, 46 individuals who are no longer with us, who had families, who were likely trying to find a better life," Nirenberg said. "And we have 16 folks who are fighting for their lives in the hospital. Our focus right now is to try to bring aid to them as best we can. This is nothing short of a horrific human tragedy."

McManus said it was the largest number of dead from a human smuggling incident in San Antonio that he knew of.

Archbishop Gustavo Garcia-Siller lamented the news in a Tweet Monday evening.

"Our prayers raised up to you, O Lord, for their souls," Garcia Siller wrote. "Lord have mercy on them. They hoped for a better life. Lord after Uvalde and now this, help us! We need you! So many people suffering."

Human smuggling has had tragic consequences before in San Antonio.

In July 2017, authorities found 39 undocumented immigrants in a sweltering tractor trailer in the parking lot of a Walmart on the South Side. Eight were already dead, and two more died later at area hospitals.

A Kentucky trucker who transported the immigrants from Laredo to San Antonio later was sentenced to two concurrent life sentences without parole. He had pleaded guilty to two counts of conspiracy to transport undocumented immigrants for profit, resulting in death.

At the trucker's trial, witnesses testified that immigrants were told that, as soon as the tractor-trailer left Laredo, the cooling system would turn on. But it never did.

As temperatures rose in the trailer, the desperate migrants tried to cut holes in the side with keys, a knife and their bare hands. "Someone tried to claw their way through. There was blood everywhere," a federal agent testified. "You could tell they just shredded their hands."

In June 2018, more than 50 immigrants were discovered in an air-conditioned tractor trailer parked in an alley in the sedate Leland Terrace subdivision on the North Side. The migrants ran from the truck in an attempt to elude police officers, jumping over fences and climbing on the roofs of houses. More than 50 were apprehended.

As the scope of San Antonio's latest human-struggling tragedy became clearer Monday night, politicians on both sides of the country's partisan divide were quick to cite it in support of their favored policies on immigration.

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Gov. Greg Abbott tweeted: "These deaths are on Biden. They are a result of his deadly open border policies."

Gubernatorial candidate Beto O’Rourke, Abbott's Democratic opponent in November's general election, said the incident illustrates the need for immigration reform.

"We need urgent action — dismantle human smuggling rings and replace them with expanded avenues for legal migration that reflect our values and meet our country's needs," he said in a Tweet.

U.S. Rep. Joaquin Castro (D-San Antonio) said on Twitter that the calamity showed "we must end Title 42, which has put desperate, oppressed people in grave danger of death."

He was referring to a provision of U.S. public health law that first the Trump administration and now the Biden administration has used to turn away asylum seekers at the border, ostensibly to halt the spread of COVID-19. Biden wants to end the policy, but courts have prevented it.

Like Abbott, Matt Mackowiak, a Republican political consultant in Austin, traced the disaster to supposedly weak border enforcement by Biden. "Open borders lead to immeasurable human suffering and death," he tweeted.

Staff Writers Eli Trovall and Madalyn Mendoza contributed to this story.