Authorities uncovered nearly a dozen illegal immigrants stripped down to their underwear in a San Antonio stash house Sunday – the same day officials found 10 dead and 29 injured in the back of semi-truck parked at a local Walmart.

Officers with Homeland Security Investigations and the Department of Homeland Security raided 115 Westhaven Palace with a search warrant July 23, and they found 11 illegal immigrant men in their underwear, KSAT reports.

Among the group was Jesus Antonio Martinez-Cerda, who told officers he was stripped down because “his clothes were in the washer.” One of the men held captive said Martinez took off his clothes “to blend in as an undocumented alien,” according to the court affidavit.

Martinez apparently confessed to his role in the scheme.

“Martinez stated that he is a citizen and national of Mexico having entered the United States illegally four years ago. Martinez stated he has been working at the residence on Westhaven for about three weeks,” the report read. “Martinez stated that he is responsible for feeding the (undocumented aliens) and arranging the payment of the smuggling fees.”

Investigators also nabbed Ismael Benavidez at a nearby gas station, and he allegedly admitted to feeding the revolving group of illegal immigrants at the home for the last two months, KSAT reports.

“Benavidez further stated that Martinez paid him $200 per week to feed and look after the undocumented aliens while smuggling fee arrangements were made,” court records allege.

Benavidez alleged Martinez forced the illegal immigrants to strip down to prevent them from attempting to escape.

One of the men found at the home told officers he came into the U.S. from Mexico on July 16 and agreed to pay $3,500 to make it happen, $2,500 of which he still owed. Another man among the group, from Honduras, reportedly paid the same amount.

Both men said Martinez picked them up with other illegal immigrants and brought them to the home.

Martinez and Benavidez now face charges of transporting and harboring undocumented aliens and were ordered detained at bail hearings Monday. Two illegal immigrant from the house were also detained as witnesses, My San Antonio reports.

The incident occurred on the same day dozens of illegal immigrants were found sweltering to death inside a semi-trailer parked at a Walmart in southwest San Antonio.

A total of 10 of at least 39 illegals found in the trailer died as a result and 29 were hospitalized.

“Thomas Homan, acting director of U.S. Immigration and Customs Enforcement, said there may have been more than 100 people in the truck. Only 39 were found inside the trailer and one in the wooded area nearby,” according to the news site. “Officials believe the rest left the scene.”

A massive response effort – including cops ambulances, 29 firetrucks and two AirLIFE helicopters – unfolded after a Walmart employee encountered a disoriented and dehydrated person in the parking lot asking for water. The person told the employee there were people inside the trailer who needed help.

Police arrived around 12:30 a.m. and arrested the driver, James Matthew Bradley Jr., at the scene.

Eight were found dead in the truck, two others died from heat-related illnesses at the hospital, KENS reports.

Bradley now faces up to life in prison or death and a $250,000 fine for a single count of transporting illegal aliens, U.S Attorney Richard Durbin, Jr. told the news site.

Several of the injured remain in the hospital.