US congresswoman Alexandria Ocasio-Cortez was moved to tears by the testimony of a woman whose 19-month-old daughter died after being detained by immigration authorities.Yazmin Juarez told a House oversight and reform hearing in Washington that she had left her home in Guatemala to seek a safer life in the US. Instead she saw her baby Mariee die. After the pair were detained by US Immigration and Customs Enforcement (ICE) last spring, they were held with 30 other people including sick children, Ms Juarez said. Despite being healthy beforehand, she said her daughter fell ill with a high fever, vomiting and diarrhoea.Nurses at the south Texas family residential centre in the city of Dilley – the largest such facility in the US – failed to thoroughly examine the child, Ms Juarez said, merely sending her away with painkillers.Mariee eventually died of a lung infection some weeks after they were released, having spent two weeks in custody.Her death was “like they tore out a piece of my heart”, Ms Juarez said. “I wanted to have a better life for her and a better future so that she could keep growing, but now we won’t be able to do that and she is gone.”She added, through a translator: “There are days I just want to give up. It’s been so painful for me to see so many children and not my little girl.”Ms Juarez said she missed being hugged by her daughter.As she recounted her story, tears could be seen rolling down Ms Ocasio-Cortez’s cheeks. The 29-year-old Democrat, who became the youngest woman ever elected to Congress last year, was seen wiping them away with a tissue. Six children have died in government detention in recent months, either in the custody of Border Patrol, where people are first held when they cross the border, or that of Health and Human Services, the agency responsible for sheltering unaccompanied children.Ms Juarez has filed a legal claim seeking $60m (£48m) from the government over her baby’s death. She said she had testified because she wanted everyone to know about the conditions in which people are held under Donald Trump‘s administration after they migrate to the US or seek asylum.Lawyers, doctors and government documents have brought to light claims of people being served spoiled food, wrongly isolated, held in cells filled to double their capacity and denied access to showers while being detained for more than a month.Children have been made to sleep on the floor, blocked from washing their hands and refused clean clothes despite being kept in sometimes squalid cells.Mr Trump’s hardline stance on immigration has been one of his signature policies. Last week, he tweeted: “If Illegal Immigrants are unhappy with the conditions in the quickly built or refitted detentions centers, just tell them not to come”.Additional reporting by agencies