For the first time since combat officially ended in 2011 a United States service member was killed in Iraq.

It happened early Thursday when elite American and Kurdish forces raided an ISIS prison and released 70 people facing “imminent mass execution” in the northern region of the country. It’s also the first casualty in the war against the infamous jihadist group, an effort that launched last year.

More from the Washington Post:

In a statement, [Pentagon press secretary Peter] Cook said that U.S. helicopters flew the Kurdish forces to the town of Hawija, well south of Iraq’s largely autonomous Kurdish region. The hostages freed included more than 20 members of Iraqi security forces, Cook said. Five Islamic State militants were captured and at least 10 were killed, officials aid.

One U.S. service member was wounded when Islamic State forces opened fire on the Kurdish and American forces, Cook said, and later died. Four Peshmerga were wounded.

The American forces who took part in the raid were members of the U.S. Army’s Elite Delta Force, officials said.