The acting head of the Department of Homeland Security on Wednesday was accused of overseeing the “intentional” deaths of five migrant children, in an aggressive line of questioning by a Democratic member of the House Committee on Homeland Security.

Rep. Lauren Underwood, an Illinois Democrat serving her first term, called the deaths the logical result of “a policy choice being made on purpose by this administration,” an assertion that Acting Homeland Security Secretary Kevin McAleenan disputed as “an appalling accusation.”

McAleenan, who was first tapped to replace outgoing secretary Kirstjen Nielsen in April, previously served as commissioner of Customs and Border Protection, where he was an architect of the administration’s policy of separating migrant children from their families. That policy, Underwood said, as well as a spate of recent deaths of children in DHS custody, amounts to more than simple administrative negligence.

“People keep dying, sir. People keep dying,” Underwood said at the conclusion of five minutes of aggressive questioning, disputing that overcrowding and lack of access to medical treatment at migrant detention facilities is the result of a lack of appropriations. “Congress has been more than willing to provide the resources and work with you to address the security and humanitarian concerns, but at this point, with five kids that have died, 5,000 separated from their families, I feel like—and the evidence is really clear—that this is intentional. It’s intentional.”

As colleagues protested her characterization, Underwood continued, calling the deaths “a policy choice being made on purpose by this administration, and it’s cruel and inhumane.”

McAleenan, who co-authored a memo to then-Secretary Nielsen asserting that Homeland Security could “direct the separation of parents or legal guardians and minors held in immigration detention so that the parent or legal guardian can be prosecuted,” protested Underwood’s remarks.

“That’s an appalling accusation, and our men and women fight hard to protect people in our custody every single day,” said McAleenan, adding that Congress providing adequate resources “would have prevented this from happening.”

Republican committee members—as well as one Democrat, Rep. Elissa Slotkin of Michigan—voted to strike Underwood’s remarks from the congressional record.

On Monday, a 16-year-old Guatemalan boy became the fifth minor to die in U.S. government custody since December after being kept in a U.S. Customs and Border Protection detention facility for more than a week. Federal law requires minors to be held in Border Patrol stations, which are not equipped to house children or the infirm, for no longer than 72 hours.