Pupils at St Stephen's College Preparatory School in Stanley were evacuated yesterday when workmen on the campus dug up a British wartime bomb. The bomb was about 60cm underground. Police evacuated 180 pupils, as well as staff and parents attending a school conference, and cordoned off Wong Ma Kok Path. The bomb was destroyed in a controlled explosion at 9pm. The blast shattered windows and damaged a canopy. Bomb disposal officer Alick McWhirter said the bomb could have caused damage over a 30-metre radius.