On Dec. 8, 7-year-old Jakelin Caal Maquin died of dehydration and shock after 36 hours in detention. Last week, a 5-month-old infant was reportedly hospitalized with pneumonia shortly after being released from custody.
Felipe and his father were apprehended several miles from the Paso del Norte Port of Entry in El Paso, Texas, on Dec. 18, according to a CBP statement. They were transferred from the processing center there to the El Paso Border Patrol Station two days later and then, on Saturday, to a station in Alamogordo, New Mexico. The boy died just before midnight on Monday in that city.
House Speaker-designate Nancy Pelosi (D-San Francisco) said Congress will investigate the deaths.
"We all have a moral responsibility to ensure all children of God are treated with compassion and decency. The death now of two children in U.S. custody is unconscionable," Pelosi said in a statement.
Pelosi and Rep. Barbara Lee (D-Oakland) are calling on Homeland Security's Inspector General to investigate Felipe's death.
"My heart is with Felipe's family and loved ones in the wake of this unimaginable loss," Lee said.
Rep. Zoe Lofgren (D-SanJose) said Democrats plan to scrutinize the CBP's use of short-term holding facilities.
"This is heartbreaking and outrageous," said Lofgren, who is expected to chair the House Judiciary's subcommittee on immigration and border security when Democrats take control of the House in January.
"As Americans try to enjoy Christmas with our own families, thoughts of this Christmas tragedy emphasize how short we are in upholding American values regarding the treatment of migrants, especially children," Lofgren said in a statement to KQED.
"The CBP short-term holding facilities are no place for children," Lofgren said.
Local immigrant advocates say the death is a result of the Trump administration's treatment of migrants as criminals.
"Because of our policies, a young boy lost his life. A family on Christmas was devastated," said Aarti Kohli, executive director of the Asian Law Caucus. "I'm both incredibly heartsick and angry that we continue on this path of destruction."
Border agency officials say they do not know the cause of Felipe's death.
"This is a tragic loss," McAleenan said. "On behalf of U.S. Customs and Border Protection, our deepest sympathies go out to the family."