Daniel Joseph O’Donnell, 69, died on April 3, 2015.Dan was born on Oct. 5, 1945, in Pittsburgh, Pennsylvania, to John Howard O’Donnell, M.D. and Mary Lois O’Donnell. He was the oldest of seven children, brother to Patricia, Brian, Mary, Ronan, John and Neil.Dan enlisted in the United States Marine Corps in Au¬gust 1965. Commissioned through Officer Candidate School, he served in Vietnam as an infantry and reconnaissance officer with the First Force Reconnaissance Company from November 1967 through December 1968. During his time in Vietnam, he served as a platoon commander, combat diver and intelligence officer. He was awarded the Bronze Star for combat valor, the purple Heart, the Presidential Unit Citation and the Vietnamese Cross of Gallantry. He was honorably discharged from the reserves as a captain in 1973.Following his military service, Dan graduated from the University of Pittsburgh School of Medicine in 1975. He had a long career, both in academics and private practice, as a psychiatrist and medical director before entering the field of healthcare information technology. He served as the senior advisor for medical informatics at InterSystems from 2008 until his death.Dan’s many passions included music, history, literature, riding, skiing and traveling. An avid violinist, he was never without his instrument. His greatest pleasure and pride in life, however, was his wife of 30 years, Joan McIlhenny, and their children, Alan, Philip, Hannah and Helen.He will not simply be remembered. He will stay an intrinsic part of our lives and our way of thinking, a lasting inspiration and example. He was a constant source of security, steadfast love and ceaseless wisdom for all of us, and it was unimaginable that there would come a day when he would not be with us. We will miss him always.In accordance with Dan’s last wishes, there will be no service.In lieu of flowers, please consider making a gift to The Juilliard School, or the wounded Warrior Project.