A Department of Public Safety (DPS) trooper discovered nearly 90 illegal immigrants packed like human cargo in the back of a tractor-trailer in South Texas. The discovery came following a traffic stop.

The DPS trooper stopped an 18-wheeler headed northbound on U.S. Highway 77 near Raymondville, Texas, on Tuesday night. After obtaining permission to search the vehicle, the trooper found nearly 90 illegal immigrants locked in the truck’s trailer with no way of escape. After finding the human cargo, the trooper called Border Patrol officials and emergency medical services to evaluate and treat the migrants, ValleyCentral.com reported.

Shortly after the discovery, migrants were seen climbing to the top of the trailer. Responding firemen provided a ladder to get them safely back on the ground.

EMS officials told the local CBS affiliate that they transported two of the migrants to hospitals in the area. He said they also evaluated and treated 86 other migrants at the scene for dehydration and heat exhaustion.

Willacy County EMS spokesman Frank Torres told the reporter that “It was heat exhaustion and dehydration that was the primary concern or complaint that was heard from the patients we treated.”

An emergency medical hospital landed on the highway during the investigation. It was not reported if any migrants were transported via helicopter. Ambulances were called from agencies throughout the Rio Grande Valley, Torres explained.

Torres said a driver and his passenger were taken into custody but he did not know which agency took custody of the alleged human smugglers.

Border Patrol agents arrived on the scene and could be seen preparing to move the migrants to a detention facility for processing.

Torres said a Customs and Border Protection helicopter appeared overhead for a little while and that a drone was also flying. It was not reported if any of the migrants fled.

Border Patrol officials told Breitbart Texas they are relieved that no one lost there lives while being locked in the back of this trailer.

Last summer, nine illegal immigrants lost their lives after being locked in a trailer during a trip from Laredo to San Antonio, Breitbart Texas reported in July. Eight of the migrants died in the trailer. The ninth died after being transported to a San Antonio hospital.

A similar incident occurred about ten days prior to the San Antonio case when Houston Police Department officers found 12 migrants locked in an abandoned trailer in the sweltering heat of Texas summer.

Harris County District Attorney’s Office First Assistant Tom Berg said, “Thirty more minutes and this could have been a dozen homicide cases.”