The Trump administration may have already deported parents of hundreds of detained immigrant children, new government data shows. Both the government and non-profit groups are struggling to locate those parents now, at the risk of never reuniting them with their kids.

The US government is scrambling to meet a court deadline to reunite families it separated under the Department of Justice’s “zero tolerance” policy. The process has been just as chaotic as the original separations, immigration lawyers said Tuesday during a conference call arranged by FWD.US, a pro-immigration group funded by the tech industry. Church groups and NGOs are also stepping in to assist in the reunification process, which is supposed to conclude on July 26.

But immigration attorneys worry that some children may never be reunited with their parents. Activists said Tuesday that that reunification is proving particularly tough in cases where kids are too young to tell anyone their parents’ names or where they are from. “The ability of an infant or a one-year-old to identify a parent gets quite difficult,” said Alida Garcia, coalitions and policy director for FWD.us.

The Department of Health and Human Services said in a court filing late Monday (July 23) that hundreds of the over 2,500 detained immigrant children (aged 5 to 17) are still not with their parents.

“This is the disaster that the government wanted to happen,” said Jennifer Falcon, spokesperson for the Refugee and Immigrant Center for Education and Legal Services, or RAICES, which said today American citizens have donated $3 million to pay for reunification efforts.

Immigration and Customs Enforcement, or ICE, has been removing parents from detention but the reunification process has not kept up. Some parents have reportedly been forced to wait in other holding facilities while their kids are located, while others say they were told to sign papers agreeing to deportation, in order to see their kids.

“We’re having a really hard time keeping track of our clients when they’re released,” said Falcon. One of the women RAICES represents said her daughter was told “Your mother decided to be deported without you. She no longer loves you and doesn’t want you,” she said.

On July 12, the court-ordered deadline for any children under age 5 to be returned to their parents, government lawyers said that some children could not be reunited because their parents had already been deported. It is unclear whether and when those families will ever be reunited.

Some detainees or their family members in the US have also had to take out high interest loans in order to buy plane tickets to reunite parents with their children. “It’s extremely expensive, and families have no other choice,” said Jessica Morales Rocketto, political director of the National Domestic Workers Alliance, another non-profit working with on family reunification.