In the 20th century several changes took place, with the Ballroom becoming a cinema, until the Society for the Protection of Ancient Buildings became the owners in 1931. The building was restored by A Mowbray Green in 1938, with Oliver Messel as the interior designer. During the Bath Blitz of 25/26 April 1942, one of the retaliatory raids on England by the Baedeker Blitz following the RAF's raid on Lübeck, the Assembly Rooms were bombed and burnt out inside. After the cessation of hostilities in Europe, they were restored by Sir Albert Richardson, with work being completed in 1963. The ballroom ceiling had to be repaired after it collapsed in 1989.