By Rooney Mara and Joaquin Phoenix for PEOPLE:

“Last week, we learned that the parents of 545 children separated at the border by immigration officers have not yet been found. The weight of that number is staggering. Five hundred forty-five children.

Like many, we were pained to realize that despite falling out of the headlines, the policy of family separation continues to damage children and parents across the world, more than two years after it was ruled illegal by a federal judge.

As new parents, it’s unbearable to imagine what it would feel like to have our child taken away from us for a day, let alone years. But that’s the very situation those 545 children and their parents have been living through. As Americans, it’s our responsibility to continue paying attention to the plight of these families and get answers for why they still have not been located.

The practice of taking children away from their parents at the border was intended to be a deterrent. Many of the families subjected to it were asylum-seekers — meaning they came to the U.S. looking for our help after fleeing violence and danger at home. Instead, in order to send a message to other families who were on the run, we took their children away from them hoping that word might filter back home that new peril awaited anybody looking to make a similar journey.

In some cases, this meant quite literally ripping children younger than 5 out of the arms of their parents, even babies under a year old. We all remember the audio that was leaked of some of those children in government custody wailing for their parents.

The ACLU [American Civil Liberties Union] sued the government over the family separation policy — known as “zero tolerance” — eventually winning a court order mostly halting it in late summer 2018. As part of the case, the government was told it had to hand over a list of separated parents to the ACLU and its partners so they could track them down and help them find their kids.

The government grudgingly handed over that list, which showed that more than 2,700 children had been taken away from their parents under the policy. But more than six months later, a whistleblower report from the Health and Human Services Office of the Inspector General revealed that the true number was far higher. In fact, thousands more had been separated during an informal test run for the policy during 2017 and early 2018.

Attorneys for the government fought to keep the public from learning about the existence of these children. And it’s not hard to grasp why. In many cases, their parents were deported to their home countries after the separations while the children remained in the U.S. Those were the parents whom immigration officials hoped would spread the message: If you come to America, they will take your children from you.”

Read more at PEOPLE.