The U.S. Department of Defense declared a missing soldier dead Thursday after a U.S. Army UH-60 Black Hawk helicopter crashed last week near Yemen.

Staff Sgt. Emil Rivera-Lopez was previously listed as Duty Status Whereabouts Unknown on Aug. 25. According to a DoD press release, Rivera-Lopez was involved in a training incident off the coast of Yemen, where the soldier was supporting U.S. Central Command operations.

Senator John McCain confirmed in a tweet Saurday that Rivera-Lopez was from Tucson.

Later in the day, Senator Jeff Flake also expressed his condolences for Rivera-Lopez.

According to the U.S. Army, Rivera-Lopez was 31 years old. He was born in San Juan, Puerto Rico. Rivera-Lopez enlisted in the Army in 2006 as a 15T, UH-60 Black Hawk Helicopter Repairer. He attended basic training at Fort Jackson, South Carolina and Advanced Individual Training at Fort Eustis, Virginia.

The incident remains under investigation.