SAN ANTONIO (WOAI/KABB) — A multi-agency investigation is underway after a body was discovered near railroad tracks in Southwest Bexar County on Monday afternoon.

The body was discovered by authorities near Pue and Wolf Road around 1:30 p.m., according to the Bexar County Sheriff’s Office.

BCSO said that on Saturday, a woman who was traveling on a train originating in Del Rio called her sister, who was out of state, and told her the boxcar was overheating.

Her sister reported it to the San Antonio Police Department, which responded but did not find anything on Saturday, sources said.

When the train arrived in San Antonio, the train split. Some boxcars went to Laredo, while some went to other destinations.

RELATED: Six people confirmed dead in Union Pacific cargo train at Laredo railyard

We’re told six people who were found on a Union Pacific train in Laredo on Sunday afternoon are believed to have been connected to the train that originated in Del Rio and split in San Antonio.

BCSO said that a sensor was tripped, and near there is where they found the body of a male this afternoon, who is believed to have been on the same train that originated in Del Rio.

The Bexar County Medical Examiner is working on identifying the man. Sheriff Javier Salazar did say the man had a Mexican voter registration card.

Investigators believe the man was being smuggled. We have reached out to Homeland Security Investigations, which is now the lead agency investigating both cases.

BCSO says charges are pending. No arrests have been made as of yet. Union Pacific is also investigating.

Routine inspection leads to grim discovery in Laredo

A routine inspection led to an unexpected discovery on Sunday. Five men and one woman were found dead in a boxcar.

“On any day, it would have been a tragic event, but the fact that this happened on Mother’s Day is even all that much more sadder for us,” said Laredo Police Department Public Information Officer Joe Baeza.

Laredo police are not calling it human smuggling at this point, but are not ruling it out.

“We’re leaving it all open. Because as we do an investigation, we don’t guess. We basically make sure that we follow, follow the evidence, and we follow that, that path,” Baeza said.

Human trafficking expert Kimberly Mehlman-Orozco says that the path begins with identifying the victims, figuring out where they came from, where they were going, and if this is part of a larger operation.

“Oftentimes this isn’t just a one off. It’s not an isolated incident. and so if these people were found in the back of this boxcar, how many other boxcars are there? How many other lives are in danger?” Mehlman-Orozco said.

Another big question is whether it is human smuggling? Who got paid?

“We really are following the money and seeing how much money was paid to whom under what circumstances. I think that will absolutely be key,” Mehlman-Orozco said.

This is not the first smuggling bust in the area. In recent months and years, Laredo police have found migrants trying to enter the US through sewer systems, trapped in the back of trucks, and now, in a train car.

“It’s just becoming a common thing here in Laredo, especially being a border city, people are traveling up north, and unfortunately, they’re using Laredo as one of their entry points,” Laredo police PIO Jose Espinoza said.

Baeza said Laredo PD is handling the crux of the death investigation, the collection of evidence, and the processing of the scene.