the collapse of parts of the vaults of the northern aisle. Due to that gap, it was feared that the building could collapse totally. However, all roofs and windows were closed quite soon, and by 1950 the vaults were reconstructed and the whole building stabilized. From 1972 to 1981 the church was restored once again. During those works, the chance was used for an intensive archaeological examination of the foundations and the graves under the floor. The only change of structures was the new rose window of the northern transept, but many of the Neo-Byzantine paintings disappeared. The design of the stained glass windows is totally new. Interior Altars and pulpit On the eve of the reformation, the cathedral contained fifty altars. Now, there are four altars and one pulpit. The main altar is in the choir. For smaller services, there is a central altar beside the pulpit in the middle of the northern side of the central nave. It is decorated with a torso of a sculpture of Christ, carrying his cross, saved from northern façade. The two other altars are in the crypts. In the western crypt, nowadays used as baptismal chapel, it is decorated with the oldest sculpture of the cathedral, Jesus Christ as a ruler with Saint Peter's key. The pulpit installed in 1638 was a gift to the people of Bremen from Queen Christina of Sweden, whose troops - in the course of the Thirty Years' War - had already captured the Prince-Archbishopric of Bremen, and aimed at gaining the city too. The pulpit remains in its original location. Organs Bremen has a long-standing tradition of fine organ music. As early as in 1244, the cantor was ordered to take care of the organ. Notations are preserved since 1526. In 1528, the construction of a new "large organ" was begun. From 1698 to 1843 the famous organ built by Arp Schnitger, one of the Baroque period's best known organ makers was the main organ. Its replacements, the Schulze organ and then the Wilhelm Sauer organ, one of the largest in northwest Germany. The cathedral today has five organs in different parts of the cathedral and continues the long tradition of great organs and organists. Choir stalls Up to the nineteenth century, the cathedral choir, which still exists today, was situated in the crossing and divided from the transepts by lateral walls. On both sides of