Six people were found dead inside a cargo train boxcar in a Texas city along the southern border on Sunday, officials said.

The bodies were found in a Union Pacific train at a rail yard in Laredo, around 160 miles south of San Antonio, just after 3:30 p.m. local time, said Jose Espinoza, a public information officer with the Laredo Police Department.

The circumstances of their deaths are unknown, said Laredo police spokesperson Joe Baeza, according to CNN affiliate KGNS, and an investigation is underway.

Union Pacific operates across the border and is the only railroad that services all access points into Mexico, according to the freight company’s website.

Temperatures on Sunday afternoon in Laredo were in the low-mid 90s, though it’s unclear whether heat was a factor.

Union Pacific said it was saddened by the incident and is working closely with law enforcement to investigate.

Laredo police said they received a call around 3 p.m. from an employee at the Union Pacific rail yard, KGNS reported. The bodies were discovered during a routine rail car inspection, police said. No survivors were found.

CNN has reached out to Laredo police for more information.

“It’s a very early phase of the investigation. There’s not a lot to reveal right now,” Baeza said, KGNS reported.

The immigration status and ages of the deceased are not yet known, Espinoza said.

US Customs and Border Protection referred CNN to the Laredo Police Department, saying “The incident remains under investigation by Laredo Police Department and Homeland Security Investigation and Texas Rangers.”

CNN has reached out to the Department of Homeland Security, HSI and the Texas Department of Public Safety.

“It’s a very unfortunate event,” Espinoza told CNN. “It was too many lives that were lost.”

This story has been updated with additional information.

Gov. Greg Abbott on Sunday directed the Texas Division of Emergency Management to activate state emergency response resources as a massive storm system threatens much of the state with hurricane-force winds, giant hail, and the risk of tornadoes.

Severe weather in Texas

The severe weather, expected to last through Monday morning, covers a vast footprint including West, North, East, Central, and South-Central Texas. Forecasters warned the system could produce wind gusts exceeding 75 mph and hail larger than 2 inches in diameter.

What they’re saying:

“Texas is prepared to confront the severe storms that pose a threat to communities all across our state,” Abbott said in a statement. He urged Texans to monitor local forecasts and warned motorists never to drive through flooded roadways, invoking the phrase, “Turn Around, Don’t Drown.”

Heavy rainfall is expected to be widespread, with some areas potentially seeing isolated totals of 3 to 6 inches, which could lead to significant flash flooding. As the system progresses, the threat is expected to shift toward the South and Southeast Texas coasts.

LIVE RADAR

In preparation, the governor has deployed a wide array of state assets to assist local officials, including:

• Search and Rescue: Swiftwater and floodwater rescue boat squads and urban search and rescue teams from Texas A&M Task Forces 1, 2, and 3.
• Aviation and Marine Support: Helicopters with hoist capabilities from the Department of Public Safety and Texas Parks and Wildlife, as well as Tactical Marine Units.
• Infrastructure and Recovery: Texas Forest Service saw crews to clear debris from roads and Department of Transportation personnel to monitor highway conditions.
• Medical and Utility Support: Emergency medical task forces with ambulances and all-terrain vehicles, along with monitors from the Public Utility Commission to coordinate power outage responses.

State agencies are also monitoring the state’s natural gas supply and water quality as the storms move through.

Officials encouraged residents to assemble emergency kits and check road conditions at DriveTexas.org before attempting to travel.

A cruise ship tied to a deadly hantavirus outbreak is expected to dock in Spain within hours after days anchored off the Canary Islands, with officials reporting more than 150 infections and preparing to transfer passengers to a nearby airport for evacuation; among them, 17 Americans will be sent to the National Quarantine Unit in Nebraska for up to eight weeks of isolation, while two Texans who disembarked before the outbreak was detected are already home and monitoring for symptoms.