Don was erudite; he read widely in history and literature; and he loved music, Oriental art, and philosophy. He had an impressive collection of classical music records and was always willing to share his rare books on Buddhism and Indian art. He loved chamber music and enjoyed travel and archeology in Europe, India, Japan, and South America. His travel was often combined with work for the United Nations, foreign universities, and international conferences.
A bachelor in the earlier part of his life, Don married Phyllis Henderson in 1972. They organized and supported many chamber music performances at Caltech and enjoyed traveling together.
Don’s many achievements did not go without recognition. He was elected to the National Academy of Engineering in 1973 and to the Indian Academy of Engineering in 1987. He was president of the Seismological Society of America (1971–1972) and president of the International Association of Earthquake Engineering (1980–1984). In 1989 the American Society of Civil Engineers awarded him the Nathan M. Newmark Medal, and in 1992 the Earthquake Engineering Research Institute awarded him the Housner Medal.
Don was a patient, thoughtful, and generous gentleman. The respect and immense influence he commanded were the result of his reputation for fairness and his ability to lead through reason and unselfish motives, which were aimed for the benefit of others and for the common good. He had the ability to attract and to lead his students and coworkers with unassuming suggestions and by carefully listening to their views and ideas. His students continue to emulate and to propagate his methods and ideas on how to educate young people and new creative minds. Theodore von Kármán, one of Don’s teachers, was cited for saying that “scientists study the world as it is, but engineers create the world that has never been.” We will always remember Don as our teacher who helped create those engineers. He was a friend and communicator par excellence.