Info from kjfitz:
The four angular towers are 51 meters high and interrupt the continuity of the upper level of tiers in order to sustain the roof's main supporting beams. These red-colored metallic beams extend along the perimeter of the stadium and have a rectangular structure. They intersect at the four corners of the stadium and extend to the exterior. The main supporting beams are 9.5 meters high.
The current capacity of the stadium is 85 000 with all seats being covered. Although the East side of the stadium does not have a third tribune, designed not to interfere with a hippodrome situated next to the stadium, the atmosphere inside is awesome. The lack of this tribune enables a great view of Milan and fans sitting on the highest seats can admire the city's most beautiful cathedral.