San Antonio police said they received a call from a driver passing by Thursday night about suspicious activity on a big rig that was headed eastbound on I-10. An officer on scene initiated a traffic stop, but when he tried to make contact with the driver, the latch opened and multiple people ran out.
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In total, authorities said 29 people, including men and women, were taken into custody. One person was taken to the hospital as a precaution due to dehydration.
While it's unknown how many people were inside the big rig, authorities said they believe there were up to 100 people inside.
"That's what we're hearing. That's the guesstimate right now," San Antonio PD Lt. Jesse Salame said. "We don't have a solid number on that."
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Those in custody were provided with water and food and placed on buses headed to an undisclosed location, according to authorities.
The driver, who was among those taken into custody, could face federal charges.
An investigation is ongoing.