The officer was not immediately identified pending notification of family, and an Army statement did not give a possible cause of death, the San Antonio Express-News reported Tuesday.
The base's firefighters discovered the officer about 7 a.m. Monday while responding to a call about a water leak, the statement said.
He was found in his room at the Warrior Transition Battalion dorm, which houses hundreds of wounded soldiers.
Foul play was not suspected but was not ruled out pending an investigation, said Chris Gray, a spokesman for the Army's Criminal Investigation Command.
Notable deaths of 2014 [PHOTOS]