Winds gusting to 56 m.p.h. blasted gravel and other debris into the world's tallest building, and 90 of the Sears Tower's windows cracked or shattered, officials said in Chicago. No injuries were reported, said police and officers of Sears, Roebuck & Co., which has its headquarters in the building. Police cordoned off streets surrounding the 110-story building during the morning rush hour and planned to keep one closed throughout the day. Jones said it appeared that one or more windows, each of which are 5 feet wide and 8 feet tall, were broken by debris and the others were broken as pieces came down. He said officials did not have a damage estimate.