Robert Diaz Lopez graduated from Tolleson Union High School in 1965 where he had played football and basketball.

He joined the U. S. Navy right out of high school. He completed basic training and then went on to Corpsman training. He was assigned to a Marine Corps unit in Vietnam as a corpsman where he was killed in action on June 1, 1970.

As a Navy Corpsman, he completed Marine Combined Action Force School with the Third Marine Amphibious Force in DaNang.  Marines completing the course, which included military training, first aid, sanitation, hygiene and farming techniques, were assigned to villages and hamlets to work with and train Vietnamese Popular Forces.