Texas Congressman Joaquin Castro wants answers on what Immigration and Customs Enforcement knew about the case of a toddler from Guatemala who died after leaving federal custody earlier this year.

Castro, a Democrat, said Wednesday he will ask ICE what the agency knew about the medical condition of 18-month-old Mariee during the time she and her mother were detained at the South Texas Family Residential Center in Dilley, Texas, in March. A VICE News investigation published Monday found that Mariee entered the center healthy, and was first diagnosed with a viral infection while inside. She died in May at a Philadelphia hospital six weeks after leaving Dilley.

“I want to know what our government knew about this child,” Castro said in an interview with VICE News. “They knew that she was sick, and what did they do to prevent it? I want to know whether anyone or the facility will be held accountable for creating the conditions that led to her passing.”

Mariee and her mother, Yazmin Juárez, came to the U.S. seeking asylum and were detained at Dilley from March 5 to March 25 — the legal limit of days the government can detain children. Pediatricians interviewed by VICE News about Mariee’s vital signs and symptoms during her time in detention say the medical staff provided the necessary treatment. VICE News’ investigation found that conditions for kids in detention allow for viral infections to spread more easily, and can make it harder for sick kids, like Mariee, to recover. Mariee left Dilley and went to 2 other hospitals before she died from viral pneumonitis after being taken off life support on May 10 at Children’s Hospital of Philadelphia.

Juárez told VICE News she had to wait hours, and sometimes days, for medical treatment at Dilley in an over-air conditioned gym with hundreds of other sick detainees. She grew so concerned about Mariee’s condition that at one point she said she asked officials to send them back to Guatemala so she could take Mariee to a hospital.

Earlier this summer at a meeting with the Hispanic Caucus, Department of Homeland Security Secretary Kirstjen Nielsen told Castro that no child had died or been seriously injured while in the government's care, Castro said.

“She either lied to me or was incompetent in not understanding that children were being placed in serious danger,” Castro said.

Lawyers for Juárez are asking for $40 million from the city of Eloy, Arizona, in a wrongful death claim. Eloy oversees the contract with the private prison company CoreCivic that operates the Dilley detention center.