Last month's small plane crash into Milan, Italy's tallest building prompted unsettling flashbacks to Sept. 11, briefly shook world financial markets and revived calls in the U.S. for greater security in air space over cities.
Italian officials dismissed fears of a terrorist link to the April 18 accident, which killed the pilot and two others and injured dozens. When the four-seat, twin-engine private aircraft punched into the 25th floor of the 30-story Pirelli Tower, it triggered fire on several floors.
Mechanical problems were cited as the most likely culprit. Air traffic control officials said the 68-year-old pilot had been in contact, complaining of landing gear problems just moments before slamming into the tower.
Although the crash and fire gutted most of two floors, and caused the 27th to collapse onto the 26th, the tower appears to have escaped serious structural damage. Officials noted that the building's major load-bearing components are at its ends, not the center, where the plane hit.
Named after the tire maker that once was headquartered there, Pirelli Tower was designed in 1956 by architect Gio Ponti and structural engineer Pier Luigi Nervi, who is known for his use of reinforced concrete. One of the world's tallest concrete skyscrapers, it currently houses government offices.
In the U.S., the accident prompted Chicago Mayor Richard M. Daley to call for reinstitution of post-Sept. 11 "no-fly zones," recently lifted over all U.S. cities but Washington, D.C.