 Due to fears of a Japanese invasion, the Queensland Government closed all coastal state schools in January 1942, and although most schools reopened on 2 March 1942, student attendance was optional until the war ended.The closed schools were sometimes occupied for defence purposes, and some schools remained closed "for special reasons" after the rest had reopened.Slit trenches, to protect students from Japanese air raids, were also dug at Queensland state schools, often by parents and staff.