Although indications were that the aircraft, with 255 people on board, came down in a tragic accident that has no connection to terrorism, the White House said officials were being "very cautious about any conclusions." They refused to rule anything out, President George W. Bush's spokesman said. The flight recorder was recovered and is being analyzed, according to reports.

Mayor Rudolph Giuliani told reporters 151 bodies were recovered and that six persons were missing on the ground, presumably residents of the houses that were hit when the airplane hit the ground.

First accounts told of an explosion or fire on board the doomed Domican Republic-bound aircraft before it crashed onto a service station in the dormitory borough of Queens, some five miles from JFK and only miles from the UN. None of the 246 passengers and nine crew survived, according to initial information. This would make it among the worst such accidents of recent years.

The flaming wreckage started fierce fires in four homes in the crowded residential community. At least 15 people on the ground were injured. More than 200 firefighters and 40 fire trucks were called to the scene.

Despite the apparent absence of any terrorist link, officials ordered a partial lockdown of UN headquarters, for security reasons. New York area airports and Manhattan's bridges and tunnels were closed for several hours. The UN campus lies in a direct line from the site of the crash and was itself declared a terrorist target when the World Trade Center was car-bombed in 1993.

Only last week Osama bin Laden said the UN is a harbor for "infidels" and called its Secretary General, Kofi Annan, a "criminal."

The lockdown, which was relaxed after about 90 minutes but not entirely lifted, kept US Secretary of State Colin Powell penned inside the already closely guarded building, along with French foreign minister Hubert Vedrine and other top diplomats visiting New York for a Monday meeting of the Security Council on terrorism and a continuing high-level session of the General Assembly. President George W. Bush made his UN debut in the General Assembly Saturday.

Both of the scheduled UN meetings went ahead Monday, but many alarmed delegates from all over the building crowded around television sets to catch news reports and view images of the burning wreckage of the aircraft and surrounding houses minutes after word of the crash swept through the conference halls and corridors.

There was a palpable sense of relief that the crash, tragic though it was, appeared in the initial analyses to have had no terrorist link or or to have resulted from a simple hijacking of the kind that used to be all too common when passengers and crew would suddenly find themselves forcibly destined for Cuba. Fidel Castro stopped those capers, seldom injurious, by arresting the hijackers on arrival in Havana.

The fact that Monday's crash was of a French-built Airbus owned by American Airlines was a new blow to that carrier. One of its Boeing jetliners was taken over by terrorists who crashed the plane into a tower of the World Trade Center in the worst such incident in history, which resulted in the loss of thousands of lives. What is clear from this first major air crash since then is that, post-Sept. 11, any civilian airplane accident, anywhere, must immediately arouse suspicions of what is now termed a "terrorist event."

The ministerial-level debate at the UN, which was postponed because of the World Trade Center and Pentagon attacks and attendant security risks for foreign visitors, finally got underway this past weekend. At once, it revived attention on the phenomenon and threat of terrorism.

This did seem to be wavering a bit as delegates had begun to focus on some other pressing questions on the international agenda. Kofi Annan himself drew attention to the fact that terrorism is not the only global problem, when the world still must grapple with the dire effects of poverty, promote sustainable development, guard against environmental degradation and fight the scourge of HIV/AIDS, which has taken not thousands of lives, but millions.

Still, it is terrorism that was the dominant theme of Bush's address to the General Assembly and that has figured largely in virtually all of the subsequent speeches by heads of state or foreign ministers, including President Pervez Musharraf of Pakistan, who has become a crucial ally of the US as the military campaign continues in Afghanistan.

Annan has repeatedly declared that excusing terrorists by calling them freedom fighters, or some such, will not wash. "Terrorism is terrorism," said the world's latest Nobel Peace laureate. In the current debate, that message seems to have acquired some resonance. While there have been the usual ritual diatribes against Israel, which some members accuse of conducting a form of "state terrorism" against the Palestinians, no one so far has seriously defended the suicide bombings and other outrages that have become a frequent response in a continuing conflict over the occupied territories.

Meanwhile, the jury still is out on the possible existence of future terrorist actions and how to thwart such threats against the US, the UN or those states that have lined up in the coalition against bin Laden and al Qaeda.

Richard Butler, who led the UN inspection teams seeking to ensure the dismantling and destruction of Iraq's weapons of mass destruction-an operation suspended by Saddam Hussein's objections to it-is convinced the Iraqis maintain a potential for bioterrorism, chemical warfare or even nuclear action and that this could be their eventual military objective. For his part, Annan has said that for the coalition to expand the current war to include an attack on Iraq would be a recipe for disaster. As of now, Powell is thought to agree with him. But there are hawkish voices among Bush's advisers who may have other ideas.

Meanwhile, there are persistent reports, including in an interview that bin Laden gave to the Pakistani newspaper Dawn, that the al Qaeda chieftain may already have acquired weapons of mass destruction. "I wish to declare that if America used chemical or nuclear weapons against us, then we may retort with chemical or nuclear weapons. We have the weapons as a deterrent," he said, according to the newspaper's account.

The US and the UK were expected to release late this week further evidence of his involvement in the Sept. 11 attacks. Despite his earlier denials, it now is reported that in a videotape he calls the towers of the 102-story World Trade Center, a famous downtown Manhattan landmark now lying in ruins, "legitimate targets."

The London newspaper, The Sunday Telegraph, published excerpts from the videotape over the week-end in which bin Laden said that if avenging the killing of "our people" is terrorism, "then history should bear witness that we are terrorists. Yes, we kill their innocents." It is against this backdrop that the alarm bells rang anew at the UN Monday, after the A-300 crash.