a model was built at a scale of 1: 1000, the employee Cordel Wehrse came up with the idea of laying a tent roof construction over the three buildings. He had become aware of Frei Otto's tent roof construction at the World Fair in Montreal through a newspaper article. Together with Carlo Weber and Heinz Isler the model was supplemented with wooden sticks and parts of a women's stocking. The architects thought of the Olympic roof as a circus tent. Finally, the model was submitted on the deadline. It was already eliminated after the first round by the jury, as it was considered too daring. However, the juror Egon Eiermann intervened and campaigned together with Mayor Hans-Jochen Vogel and NOK President Willi Daume, among others, for the model. Ultimately, the reviewers voted for the plan of Behnisch & Partner, which emerged as the winner of the competition. The decision was announced on 13 October 1967. In addition to the stadium designed for 90,000 spectators, which was then reduced to maximally 75,000. The model convinced with its surrounding landscape architecture and the tent roof construction. Thus, it fulfilled the leitmotif of the games: human scale, lightness, bold elegance and unity of the landscape with nature. In addition, the possibility of reuse was given. Even with regard to short distances, the model convinced the jury. Election To make room for the arena, the terminal building of the old airport had to be blown up. On 9 June 1969 work began on the stadium, the multi-purpose Olympic arena and swimming pool. However, it was only on 14 July 1969 with the laying of the cornerstone in a symbolic ceremony that the construction officially begun. In addition to the three buildings emerging on the Oberwiesenfeld, the Werner von Linde Hall, a volleyball hall, the Olympic Radstadion, the Olympic Village and various other buildings such as stations for U-Bahn and S-Bahn were built. During the time of the construction there was a spirit of optimism in Munich. The inner city received a pedestrian zone between Marienplatz and the Stachus and the metro was implemented. on the Oberwiesenfeld alone, there were 60 construction sites. From a total of 1.35 billion German marks, 137 million were used in the construction of the Olympic Stadium and another 170.6 million in the tent roof. About 5,000 construction workers worked at the construction site for more than one million hours.