Last month's small plane crash into...

Last month's small plane crash into Milan, Italy's tallest building activeed unsettling flashbacks to Sept. 11 briefly shook world financial markets and revived calls in the U for greater security in air space throughout cities.

Italian officials dismissed fears of a terrorist link to the April 18 accident which killed the pilot and couple others and injured dozens. When the four-seat, twin-engine private aircracft punched into the 25th floor of the 30-story Pirelli Tower, it triggered fire in succession several floors.

Mechanical puzzles were cited as the chiefly likely culprit. Air