Designed for the 1976 Olympic Games, the Olympic Stadium was not completed on time due to a strike by construction workers. The 556 foot leaning tower designed to retract the roof stood half finished until 1987 when the roof was finally completed. It took another 2 years before the roof, made from 60,696 square feet of Kevlar weighing 50 tons, became retractable. Problems with opening and closing the roof led to its permanent closure. In the spring of 1998, the original orange Kevlar roof was removed and a $26 million opaque blue roof installed. The new roof does not open. The stadium’s total cost has exceeded $1 billion. The stadium itself is a squat, oval disc supported by 38 reinforced concrete ribs , while the futuristic tower is the world’s tallest inclined structure.