Italian investigators are looking into the background of an elderly Swiss pilot who crashed his light aircraft into Milan's largest skyscraper killing three people. The crash initially caused panic, as people feared it was a terrorist attack similar to that on the World Trade Center. The authorities say inquiries so far suggest it was an accident after pilot Luigi Fasulo apparently suffered technical problems. However, speculation has been growing that he targeted the building deliberately to commit suicide. One of Mr Fasulo's two sons, Marco, told the Italian newspaper La Repubblica that his 67-year-old father had killed himself. But Mr Fasulo's nephew said he had had no reason to kill himself. "He was a person who loved life," he said. However, Italian detectives have gone to Switzerland to investigate Mr Fasulo's personal affairs.