The Bradmans lived in the same modest, suburban house in Holden Street, Kensington Park in Adelaide for all but the first three years of their married life. They experienced personal tragedy in raising their children: their first-born son died as an infant in 1936, their second son, John (born in 1939) contracted polio, and their daughter, Shirley, born in 1941, had cerebral palsy from birth. His family name proved a burden for John Bradman; he legally changed his last name to Bradsen in 1972. Although claims were made that he became estranged from his father, it was more a matter of "the pair inhabit different worlds", and the two remained in contact through the years. After the cricketer's death, a collection of personal letters written by Bradman to his close friend Rohan Rivett between 1953 and 1977 was released and gave researchers new insights into Bradman's family life, including the strain between father and son.