An Iranian missile strike on a Jordanian air base over the weekend struck prefabricated housing units where American troops lived and slept, according to U.S. officials who spoke with The Wall Street Journal.

The missile strike on Muwaffaq Salti Air Base killed two U.S. soldiers: Army 1st Lt. Tyler James Feehan, 25, of Ewa Beach, Hawaii, and Pvt. Isabella Gonzales, 19, of Carrollton, Texas.

A third service member is missing.

In the first of three missile strikes on the air base, debris struck the base's gym, U.S. officials told the Journal. Hours later, an Iranian missile hit an empty aircraft hangar. The third missile hit containerized housing units where soldiers had been sleeping, according to the report.

It is unclear whether the soldiers who died were in the housing units.

"A missile got through. We shot down almost all the missiles. One leaked through, hit the wrong place, and tragically, and it's heartbreaking," Secretary of State Marco Rubio said over the weekend when asked by reporters about the attack on Jordan.

Jordan has emerged as a new focal point in the U.S.-Iran war after four Iranian attacks in five days.

The attacks mark a significant escalation in Iran's campaign against U.S. forces in the region, bringing the conflict more directly into Jordan, one of Washington's closest Middle East allies.

The country hosts several major U.S. air bases, and its importance to American military operations has grown as other regional allies have limited U.S. access to their territory and airspace, according to U.S. officials who spoke with the Journal.

According to the Pentagon's casualty database, 427 U.S. service members have been wounded in the Iran war.