After World War II, enrollment quickly grew to more than 3,000. A large amount of housing and several academic buildings had to be built on campus. The 1950s saw the rise of the Fighting Sioux hockey tradition. In the 1960s and 1970s, many student protests occurred at UND. The largest was in May 1970 when over 1,500 students protested the Kent State shootings. In 1975, enrollment swelled to a record 8,500. The 1970s also saw the establishment of the John D. Odegard School of Aerospace Sciences at UND. During the 1980s and 1990s the University continued to grow. However, the devastating 1997 Red River flood inundated numerous buildings on campus and forced the cancellation of the remainder of the school year.