US police Tuesday were investigating the grim discovery of about 50 bodies in and around a trailer truck abandoned in sweltering heat near the Texas city of San Antonio, with victims identified as from Mexico, Guatemala and Honduras. The shocking finding was one of the worst disasters involving migrants in the United States in recent years — and came five years after a similar deadly incident in the same Texas city, a few hours from the Mexican border. The White House — facing intense pressure over its immigration policies — called the tragedy “absolutely horrific and heartbreaking,” and said President Joe Biden, flying to a NATO summit in Madrid, has been briefed on the incident. San Antonio Fire Chief Charles Hood told reporters that at least 46 victims had died and 16 people had been transported to the hospital alive and conscious — 12 adults and four children. Early Tuesday, Mexican President Andres Manuel Lopez Obrador said the toll had reached 50, mostly from Latin American nations including Mexico. “It’s a tremendous misfortune… so far there are 50 dead: 22 from Mexico, seven from Guatemala, two from Honduras and 19 still without information about their nationality,” the Mexican leader said at a morning press conference. US officials said three people were in custody over the incident. Hood, the fire chief, said survivors had suffered heat stroke and heat exhaustion, and that there were no signs of water in the truck.