Ulm converted to Protestantism during the Reformation. Ulm Minster became a Lutheran church. Despite its vast size, it is not a cathedral, as the responsible bishop of the Evangelical-Lutheran Church in Württemberg – member of the Evangelical Church in Germany – resides in Stuttgart. In 1543, construction work ceased at a time when the steeple had reached a height of some . The suspension of the building process was due to a variety of factors which were political and religious, like the Reformation, as well as economic, since the discovery of the Americas during the voyages of Christopher Columbus 1492–1504, the Portuguese discovery of the sea route to India in 1497–99, and Magellan's circumnavigation of the globe led to an epochal shift in trade routes and commodities. One result was economic stagnation and a steady decline, preventing major public expenditure. Resumption and completion of construction, 1844-1890 In 1817, the interior frescos were covered by painting the walls grey. In 1844, construction work resumed. After a phase of repairs lasting until 1856, the central nave was stabilized by the addition of flying buttresses. Then the small steeples beside the choir were built – without medieval plans. At last, the main steeple was completed, changing the available medieval plan in making it about ten metres taller. Finally, on 31 May 1890 the building was completed. World War II A devastating air raid hit Ulm on 17 December 1944, which destroyed virtually the entire town west of the church to the railway station and north of the church to the outskirts. The church itself was barely damaged. However, almost all the other buildings of the town square (Münsterplatz) were severely hit and some 80% of the medieval centre of Ulm was destroyed. Current events The church is currently dealing with problems caused by large numbers of men and women urinating around the structure. In addition to the health issues this presents, acids and salts in the urine are degrading the sandstone foundation of the Münster. Church officials say that festivals and events in the adjacent Münsterplatz draw large numbers of people to the area, but event organizers do not provide sufficient free toilets. After costly repairs to the structure, church leaders pressed city officials to increase patrols and fines, but these have failed to stop offenders. Architecture While the walls of the choir, the side aisles and the tower were constructed of brick,