Officials have confirmed that dozens of people were found dead inside of a semi trailer in San Antonio on Monday night.

The bodies were found in the trailer of a truck that was abandoned near railroad tracks in the 9600 block of Quintana Road in San Antonio, Texas, early Monday evening.

Around 6 p.m., a city worker reported hearing a cry for help near the abandoned truck and went to investigate.

“(They) found a trailer with the doors partially open and opened them up to take a look and found a number of deceased individuals inside,” said San Antonio Police Chief William McManus.

San Antonio Fire Chief Charles Hood confirmed that 46 people were found dead in the trailer. Sixteen others were found alive but suffering from heat related illness. Those people were transported to local hospitals.

Three people are currently in police custody in connection with the incident.

Temperatures climbed to more than 100 degrees in the area on Monday.

Homeland Security Investigations (HSI) has taken control of the investigation. From HSI: “On June 27, Homeland Security Investigations (HSI) responded to a call from San Antonio Police Department (SAPD) in reference to an alleged human smuggling event involving a tractor trailer on Quintana Road near Cassin Road. Upon arrival in the scene, HSI confirmed more than 40 deceased individuals.HSI San Antonio has initiated an investigation with support of SAPD. Details will be released as they are available, the criminal investigation remains ongoing.“

San Antonio Mayor Ron Nirenberg issued the following statement: “Migrants seeking asylum should always be treated as a humanitarian crisis, but this evening we’re facing a horrific human tragedy. More than 40 hopeful lives were lost. I urge you to think compassionately, pray for the deceased, the ailing, and their families at this moment.”

This is a developing story.