A 5-year-old boy staying at an overcrowded South Side shelter died Sunday, after falling ill at the shelter, police said.

Jean Carlos Martinez was transported from the shelter at Cermak Road and Halsted Street to Comer’s Children’s Hospital on Sunday just before 3 p.m., police said. He was pronounced dead there at 3:47 p.m. and an autopsy is scheduled for Monday. Detectives are investigating.

The shelter where the child was staying is a converted warehouse in Pilsen that opened in early October and has since become the single-most crowded shelter in the city, holding over 2,000 people.

It is run by Favorite Healthcare Staffing, a Kansas-based contractor the city has awarded tens of millions of dollars to run its shelters since September 2022, shortly after the first buses began arriving.

Migrant advocates are reporting that the boy died in a bathroom at the shelter after staff had refused to call an ambulance for the child.

The shelter is one of several shelters that opened earlier in the fall amid a crush of new arrivals in the city and amid a push to close police stations.

By late November, it was about as crowded as the city’s largest shelter then, holding over 1,300 people. But, another 1,000 migrants had been moved there by early December.

Migrants at the shelter quickly started sharing complaints about it with reporters and advocates, alleging it was overcrowded with many people sick and staff indifferent to conditions.

Videos from inside the shelter shared with a reporter show water leaking through the ceiling onto cots where migrants sleep and many children visibly sick, like at the O’Hare Airport shelter, first reported on by the Sun-Times in September.

Michael Loria is a staff reporter for the Chicago Sun-Times via Report for America, a not-for-profit journalism program that aims to bolster the paper’s coverage of communities on the South Side and West Side.