A 3-year-old child who was riding a migrant bus from Texasbound for Chicago died in Illinois, officials said Friday.

The child’s death is the first Texas has announced after Gov. Greg Abbott’s Operation Lone Star last year started shuttling thousands of migrants to cities including Washington, New York, Philadelphia, Denver and Los Angeles.

The 3-year-old presented “health concerns” on board the bus that departed from Brownsville, Texas, according to the Texas Department of Emergency Management, and the bus pulled over and called 911.

The child received treatment from paramedics and later died at a hospital, according to Texas’ emergency management agency. All passengers had their temperature taken and were asked whether they had any medical conditions before boarding, the agency said.

Texas authorities did not say where the child was from or why the child became ill. The Illinois Department of Public Health said the child died Thursday in Marion County, about 130 miles north of Illinois’ southern border with Missouri.

The Illinois health department is investigating the death, officials confirmed with USA TODAY.

“IDPH is working with local health officials, state police and federal authorities to the fullest extent possible to get answers in this tragic situation,” spokesperson Mike Claffey said.

Chicago Mayor Lightfoot told Abbott to stop busing migrants

Moving people to municipalities already struggling to house and support people experiencing homeless has consistently fueled criticism from cities’ mayors.