British students and teachers participate in a reading and discussion group in an air raid shelter during the height of the London Blitz. Between 7 September 1940 and 21 May 1941 there were major Luftwaffe aerial raids (attacks in which more than 100 tons of high explosives were dropped) on 16 British cities, killing more than 43,000 civilians. Over a period of 267 days, or 37 weeks, London was attacked 71 times. Beginning 7 September it was bombed by the Luftwaffe 57 consecutive nights in row. Bermondsey, South London, England, U.K. 29 March 1941.