By TOM RACHMAN MILAN, Italy (AP) - Investigators were trying to determine Friday why a small plane slammed into a Milan skyscraper, with officials calling it an accident while one report said the 67-year-old pilot may have committed suicide because of financial problems. The pilot, Luigi Fasulo, reported trouble with his landing gear Thursday and had been speaking with air traffic control before the crash, officials said, indications that terrorism was not his aim. Fasulo and two others were killed Thursday when his plane crashed into the 25th floor of the landmark Pirelli building, the tallest skyscraper in Milan. The number of injured, put originally at 60, was revised downward Friday to 36, with 11 of them still hospitalized. Fasulo's son, Marco - a pilot for the airline Swiss, told the Rome newspaper La Repubblica that his father's crash may have been a suicide induced by despair over financial problems. "It was a suicide, a suicide, do you understand?" he was quoted as saying. But Milan Chief Prosecutor Gerardo D'Ambrosio said suicide was the least credible of three possible explanations police were examining - including a technical problem or pilot illness. Italian Transport Minister Pietro Lunardi, in a Friday briefing in the Senate, said the pilot could have fallen ill at the controls. After making initial radio contact, "there was silence, he was not operating any of the plane's controls in the last two minutes," he said. The Italian air traffic controller's association said the pilot did not issue a distress signal, as previously reported. Lunardi earlier told reporters, "There's every reason to think there was something strange - the kind of target and the way it was hit straight on is spooky." Lunardi said he ordered a probe into the pilot's health, personal life and finances. The pilot's nephew, also Luigi Fasulo, told Italian state television that the crash was an accident. "Surely there was no intention on the part of my uncle to crash into the building," he said. "He was a person who loved life." The twin-engine Rockwell Commander punched a hole through the slim, 30-story Pirelli building in downtown Milan, and smoke billowed out for hours into the clear afternoon sky. The 25th and 26th floors were gutted; the sidewalks below were littered with shards of glass, office papers, broken flower pots and other debris. The crash rekindled fears of a Sept. 11-type attack. "I heard something like the engine of a plane dying out, and then I heard a terrible explosion," said Raffaele Taccogna, who was tending bar at the nearby Atlantic Hotel. "I certainly thought of the September attacks in the United States," he said. "It really looked like the same thing." Luigi Fasulo, a resident of Pregassona, Switzerland, was believed to be the only person on board the plane. The pilot - who was on a 20-minute flight from Locarno, Switzerland, to Milan - had started landing procedures at Linate airport when air traffic controllers alerted him that he wasn't lined up with the runway, the Italian air traffic controller's association said. The pilot reported "a little problem with the landing gear," and the control tower instructed him to move to the west of the airport until it was fixed, a statement from the association said. The control tower contacted the pilot again after seeing he was drifting to the north, in the wrong direction. The pilot said he was fixing the problem with his landing gear, and the tower instructed him to move back into position to approach the runway. But the pilot again didn't get into the right position, the statement said. The control tower then lost contact. Interior Minister Claudio Scajola told reporters in Rome that "initial reports point to an accident." One witness, Fabio Sunik, said the plane was on fire before it crashed. The plane flew straight into the building without deviating from its path, and "then I saw rubble falling from the building," said Sunik, a sports journalist. " Some 1,300 people work in the building, which houses local government offices, but it was not known how many where still there when the crash took place - not long after working hours ended. Officials initially said five were killed, including the pilot; however, late Thursday the vice president of the Lombardy region, Vivian Beccalossi, set the death toll at three: the pilot, a cleaning woman and a government lawyer. Rescue workers found a survivor three hours after the crash on the 25th floor, where one of the dead was found. The collision damaged a building seen as the symbol of Milan, the heart of Italy's financial and industrial world. Built in the 1950s, the 415-foot-high building once housed the headquarters of the tire giant Pirelli. The director of the Locarno airfield, Sandro Balestra, told Swiss television that the pilot owned the airplane and was an experienced pilot who was known in the area for at least 30 years. Balestra also said Luigi Fasulo's plane was instrument-equipped, but Fasulo no longer had a license to fly by instrument. The plane was a Rockwell Commander 112TC, built by North American Rockwell in the 1970s, said Wirt Walker, chief executive Aviation General Inc., which owns the company that makes an upgraded version of the aircraft. It was the second time since the Sept. 11 attacks on the United States that a plane has struck a high-rise building. On Jan. 5, a 15-year-old boy crashed a stolen plane into a building in Tampa, Fla. He was the only casualty.