At the urgent request of various bodies in 1939 it was decided remove all stained glass from the church because of imminent war danger. The cost of this operation, 9000 guilders was paid by the goverment. Between September and December 1939, all glasses were removed and replaced by ultra thick window glass. The glasses were stored in 201 specially-made boxes and kept in cellars in farms around Gouda. Then in 1943, when the war came closer, the boxes were transported to bombproof cellars in the dunes of Vogelenzang (in Noord-Holland). There they remained until the Netherlands were liberated again. In January 1947, all glasses were reinstalled and the church received its rich colours back. About this history a small exhibition is set up in the church and in the shop a booklet is available.