The U.S. military said insurgents launched an improvised explosive device attack against their unit.
Benitez spent all of his adult years in the Army. He was married with a 6-year-old daughter and a stepson. They had recently moved to Colorado, where he was stationed at Fort Carson. He served two tours of duty in Iraq and had deployed to Afghanistan in July.
His 13-year-old sister, Aimmee, remembered him "as a hero because he died serving our country" and "as a really nice guy." She said she'll miss his humor and their fun times together.
"No one ever really had anything bad to say about him," she said. "I felt safe around him. When he was there, I just felt safe. I don't consider him dead, really, because I think of him still here with us."
Benitez graduated from Creekview High School in Carrollton. He received several awards from the Army, including two commendation medals.
Benitez is also survived by his parents and a younger brother.
Spc. Rafael Martinez Jr., 36, of Spring Valley, Calif. Pfc. Tramaine J. Billingsley, 20, of Portsmouth, Va., were also killed. They were assigned to the 7th Squadron, 10th Cavalry Regiment, 1st Brigade Combat Team, 4th Infantry Division, Fort Carson.