Eight people were found dead along with 30 others inside a tractor-trailer parked at a Walmart on San Antonio’s Southwest side early Sunday morning. Two more have died Sunday since authorities discovered the truck.

“The truck was loaded with people,” San Antonio Fire Department Chief Charles Hood said in a joint press conference with SAPD. The fire department arrived on the scene at 8538 Interstate 35 Access Rd. at 12:26 a.m. on Sunday. The victims likely died as a result of heat exposure and/or asphyxiation.

James M. Bradley Jr., 60, was arrested and booked into a federal jail Sunday in relation to the incident, according to media reports. Bradley is thought to be the driver of the truck and authorities are investigating his possible role in the human smuggling scheme.

San Antonio Police Department Chief William McManus told reporters that a Walmart employee called SAPD for a welfare check after he was approached by someone from that truck that was asking for water. The employee gave the man water and then called for help.

When they arrived on the scene, San Antonio Fire Department paramedics found eight people already dead and 20 others in “extremely critical” condition. Ten more people, Hood said, were in need of hydration, but had not suffered serious injury.  The air conditioner in the trailer was apparently not working, Hood said.

“Our paramedics and firefighters found that each patient had heart rates over about 130 beats per minute and were very hot to the touch,” Hood said.

The high temperature on Saturday reported by the Weather Channel was 100 degrees. The temperature inside the unconditioned trailer sitting on the asphalt was likely much hotter.

“We’re very fortunate that there weren’t 38 of these people trapped inside this vehicle found dead,” Hood said.

Eight people were pronounced dead at the scene, and their bodies were taken to the Bexar County Medical Examiner’s Office to determine exact cause of death, though initial reports state that all were heat-related.

The injured were transported, some by helicopter, to area hospitals.

“Seventeen victims were taken to University Hospital and SAMMC with life-threatening injuries. Thirteen victims were taken to five other area hospitals with non-life threatening injuries,” according to a statement from SAPD.

Further information on the ages and country of origin of the victims was unclear at the time of the rescue. SAPD has confirmed that two were as young as 15 years old.

SAPD is reviewing surveillance videos, which McManus said show various vehicles pulling up to the truck throughout the evening, and taking passengers away. Councilman Rey Saldaña (D4), whose district includes much of the Southside including the Walmart where the truck was parked, said that conversations with police led him to believe that the drivers of the pick-up vehicles were not members of the San Antonio community, but parts of larger operation “without fixed locations or contacts.”

The driver of the tractor-trailer is in custody and faces state and federal charges.

“We’re looking at a human trafficking crime,” McManus said.

U.S. Department of Homeland Security and U.S. Immigration and Customs Enforcement will work with SAPD’s Homicide Unit to investigate the incident. After an initial search of the area around the Walmart, it is not known whether others escaped the truck before it was discovered by police. A daylight search will be conducted on Sunday, McManus said. The truck remained in the Walmart parking lot until mid-morning on Sunday when it was towed away for further investigation.

Refugee and Immigrant Center for Education and Legal Services (RAICES) criticized SAPD for calling the federal government before involving migrant support organizations such as itself.

“Instead of offering a humanitarian response, SAPD called an enforcement agency with its own track record of causing migrant deaths and criminalizing, detaining, and deporting vulnerable populations,” the nonprofit stated in a news release. “We resist all attempts to dehumanize the survivors of this tragedy. RAICES offers our legal services to all of the survivors as they seek justice and protect themselves against all attempts to criminalize, detain and deport them.”

RAICES is organizing a candlelight vigil Sunday at 6 p.m. at San Fernando Cathedral in Main Plaza.

“The care and welfare of the victims was our top priority,” an SAPD public information officer stated in response to the RAICES comments. “SAPD officers administered first aid, helped rescue those that were still inside the trailer, and cleared the parking lot so that Airlife could quickly land and transport those with the most serious injuries. DHS is the lead investigative agency for all smuggling cases. Now is not the time to point fingers and politicize the tragic loss of human life. We will continue to do our part to ensure all people in our city are protected, regardless of their citizenship status.”

“San Antonio firefighters and police responded to a horrific scene this morning on the Southwest Side of town. They discovered an alien smuggling venture gone horribly wrong, ” stated Richard Durbin Jr., U.S. Attorney for the Western District of Texas. “Eight immigrants were found dead. At least twenty more were in serious condition. All were victims of ruthless human smugglers indifferent to the well-being of their fragile cargo. The South Texas heat is punishing this time of year. These people were helpless in the hands of their transporters. Imagine their suffering, trapped in a stifling trailer in 100-plus degree heat. The driver is in custody and will be charged. We will work with the Homeland Security Investigations and the local responders to identify those who were responsible for this tragedy.”

McManus urged anyone who encounters potential instances of human smuggling, or individuals who appear to be fleeing such conditions to call 911.

“This is not an isolated incident,” McManus said. “This happens quite frequently.”

Saldaña woke up to a call from McManus at 2:30 a.m.

“While arriving on scene, I was struck with the gut wrenching reality that dozens of individuals were suffering in an enclosed trailer under the insufferable Texas heat. It should sadden us all that eight people took their last breath, and dozens more are being treated with serious symptoms of heat exhaustion and dehydration due to a tragic situation that often goes unnoticed,” he stated. “These individuals were victims of ruthless human smugglers indifferent to the well-being of their fragile cargo. Unfortunately, the sad reality is that this unthinkable journey was perhaps the best alternative for individuals looking for a better life.”

Mayor Ron Nirenberg issued a statement:

“We are still learning about the tragic events that unfolded on our doorstep overnight, which shines a bright light on the plight of immigrants looking for a better life and victims of human trafficking. As we work to coordinate a humanitarian and legal response to this terrible tragedy, I find comfort in the compassionate response of our first-responders, our local medical professionals and the outpouring of support from our community. I want to thank the Walmart employee who provided water and called 911, an act that helped us prevent more deaths.

“We will continue to work closely with local groups and federal agencies to offer support to the survivors and connect them with their families. Our thoughts and prayers go out to everyone who was impacted by this terrible loss of life. Our response should serve as a lesson to the world that San Antonio will not turn its back on any man, woman or child in need.”

Bekah McNeel is a native San Antonian. You can also find her at her blog, FreeBekah.com, on Twitter @BekahMcneel, and on Instagram @wanderbekah.