In the early 1900s the Museum's board of directors bought all the houses surrounding it, knocked them all down and built over them. In 1939, just before the start of World War II, most of the Museum's exhibits were taken to other places because the directors were worried the Nazis might bomb the Museum during the Blitz. The exhibits were stored in old London Underground stations, as well as other places. The evacuation proved to be a good idea, as parts of the Museum were destroyed by bombs in 1940.