Associated Press
Terence Hildner

FORT HOOD, Texas — A 49-year-old brigadier general died Friday in Afghanistan of apparent natural causes, becoming the highest-ranking U.S. soldier to die there, the military said Saturday.

Fort Hood announced Brig. Gen. Terence Hildner's death in a statement posted on its website. Hildner had commanded the 13th Expeditionary Sustainment Command at Fort Hood since August 2010. He left for Afghanistan in December to support the NATO mission there.

Pentagon spokeswoman Tara Rigler confirmed Hildner was the highest-ranking officer to die in Afghanistan. A Department of Defense list posted online of deaths in Afghanistan did not include any other generals.

The Army said Hildner's death was under investigation, although it appeared natural.

"This is a tragic loss for the Army, III Corps and for our Central Texas community," Lt. Gen. Don Campbell Jr., Fort Hood's commanding general, said in a statement. "Our thoughts and prayers are with his family and friends."

The 13th ESC led by Hildner supports other units, handling the distribution of everything from clothing to ammunition and performing maintenance on equipment, according to its website. It includes the 1st Medical Brigade, which provides health care and combat medical service.

Hildner served in Iraq during both Operation Desert Storm and the 2003 U.S.-led war. He also served in Kuwait and was part of the last U.S. patrol along the East-West German border before its reunification.

He assumed command of the 13th Corps Support Command's Special Troops Battalion at Fort Hood in 2003 and was in charge during two deployments, one in Iraq and one following Hurricane Katrina.