At least 50 people were found dead in a semitruck in San Antonio on Monday. The people were migrating from Mexico, Guatemala and Honduras, and officials believe their deaths were caused by extreme heat, according to CNN.
“I am heartbroken by the tragic loss of life today and am praying for those still fighting for their lives,” Homeland Security Secretary Alejandro Mayorkas said on Twitter.
What happened: At 6 p.m. on Monday, an employee working at a nearby business heard a cry for help, discovered the trailer with the doors partly open and saw at least one body inside. He alerted officials, who made the grim discovery of just how many people were inside, according to The New York Times.
At least 46 people were dead on the scene. At least 16 others were taken to a hospital, and four have died in the hospital, per The New York Times.
Temperatures reached 101 degrees Fahrenheit in San Antonio on Monday, and there was no water or air conditioning inside the semitruck.
“The patients that we saw were hot to the touch,” said San Antonio Police Chief William P. McManus, per NBC News. “They were suffering from heat stroke, heat exhaustion.”
Record-breaking migration: U.S. Border Patrol made 222,656 arrests along the points of entry in the U.S. in May, making it the highest number of arrests of migrants in a single month recorded since 2000, The Washington Post reported using a U.S. Border Patrol apprehensions list.