The death of an 8-year-old girl in U.S. Border Patrol custody in May was a "preventable tragedy" that raises "profound concerns" about the government's system of caring for migrants along the southern border, an independent federal court monitor said in a report Tuesday.

A "series of failures" by Customs and Border Protection employees and contractors resulted in the death of Anadith Danay Reyes Alvarez, a Panamanian-born girl who crossed the U.S.-Mexico border in Texas with her Honduran parents and siblings, according to Dr. Paul Wise, the independent monitor.

Appointed by the federal judge overseeing the landmark Flores court settlement, which governs the detention of migrant children in U.S. custody, Wise is charged with ensuring Border Patrol facilities are complying with the agreement and providing basic services to minors. In his role, Wise inspects Border Patrol facilities that house families and unaccompanied minors.

The report filed by Wise in the federal district court in Los Angeles adds to growing and damning evidence of serious shortcomings in the steps that Border Patrol staff and contractors took — or failed to take — before Reyes Alvarez died on May 17 in the agency's custody.

"This report concludes that the death of this child in custody was clearly preventable," said Wise, who is a pediatrician. 

Reyes Alvarez, who suffered from sickle cell anemia and a heart condition, and her family members were first processed by Border Patrol near Brownsville, Texas, on May 9. The family was detained for over a week, despite an internal rule against holding migrants beyond 72 hours.

During her week in detention, Reyes Alvarez requested medical attention multiple times because she was having trouble breathing and experiencing pain, fever and flu-like symptoms, according to her family and preliminary government reports. Her fever peaked at 104.9 degrees the day before she died, officials have said.

At the last place she was held, a Border Patrol facility in Harlingen, Texas, Reyes Alvarez was seen by medical contractors at least nine times. Her mother repeatedly asked for her sick daughter to be transported to the hospital, but her pleas were not heeded. In fact, the government has said the nurse contractor at the facility denied at least three ambulance requests. 

It was not until Reyes Alvarez had a seizure that day that officials requested an ambulance. The child was pronounced dead soon after.

"The events in the Harlingen Station resulting in [Anadith's] death raise a series of other profound concerns regarding not only the direct care she received but also the custodial and medical systems that failed to prevent [Anadith's] clinical deterioration and death," Wise wrote in his report.

Wise said staff at the Harlingen facility should've consulted an on-call pediatrician or taken Reyes Alvarez to a hospital with "expertise in pediatric specialty care" as soon as she was transferred there because of her sickle cell anemia. Wise said it was unclear whether Reyes Alvarez was monitored or whether staff at the facility were even aware of her medical history since it was not recorded.

"Medical staff do not routinely enter the holding cells to assess vital signs or other indicators of clinical deterioration," Wise said.

Wise said he did not know why staff at the Harlingen facility were "so reluctant to transfer" Reyes Alavarez to a hospital. But he cited general concerns from Border Patrol agents at some facilities of transferring migrants to a hospital because of the "drain" on "manpower associated with escorting families or children to outside facilities."

Wise said the concerns are "understandable," but he stressed that confronting medical staff with such concerns was "inappropriate" and "dangerous."

"The decision to transfer an ill individual to a local health facility should be based on medical criteria alone as determined by the appropriate medical personnel," he wrote.

Wise offered several suggested remedial steps in his report, including for Border Patrol to more closely monitor cases of at-risk migrants and expedite their release, streamline hospital transfer requests, increase consultations with pediatricians and improve communication among medical staff. 

While it has released some findings, including on the failure to transfer Reyes Alavarez to a hospital earlier during the day she died, CBP's Office of Professional Responsibility has continued to investigate the death. The probe could lead to disciplinary actions or criminal referrals.

The acting head of CBP, Troy Miller, ordered a review last month of cases of medically vulnerable migrants and families in detention to ensure they were promptly transferred out of the agency's custody. He also noted that CBP had prohibited some medical contractors involved in the ongoing investigation from working with the agency again, and brought in a new chief medical officer.

"The death of eight-year-old Anadith Danay Reyes Alvarez was a deeply upsetting and unacceptable tragedy," Miller said in a statement Wednesday. "While we cannot change the tragic outcome in this situation, as an agency, we must and will do better to ensure that this does not happen again."

Advocates for migrants have said Reyes Alvarez's death speaks to broader issues with how the government treats migrants.

"It should never be forgotten that Anadith's life was not seen as worth saving," said Neha Desai, a lawyer at the National Center for Youth Law, which represents migrant children in a federal court case. "Based on our extensive experience representing children in government custody, unless and until CBP treats all children's lives as inherently valuable, tragedies will continue to occur."

Camilo Montoya-Galvez

Camilo Montoya-Galvez is the immigration reporter at CBS News. Based in Washington, he covers immigration policy and politics.

Twitter