The timing could not have been worse.

Hard on the heels of an anthrax scare that is only just beginning to subside, two months almost to the day since the terrorist attacks that left America reeling, the crash of American Airlines flight 587 reminds everyone here that the things they once took for granted can no longer be relied upon.

The most up to date information suggests that mechanical failure rather than a terrorist attack was the cause of the crash.

The voice recorder recovered from the wreckage has suggested no intruders in the cockpit or disturbance at the back of the plane.

The flight data recorder and a minute inspection of the of the wreckage of the plane will reveal more.

Every time an airplane flies overhead in Manhattan it is difficult not to look up and wonder 'what if?'

An announcement that the crash was due to mechanical failure cannot come soon enough for the US government.

If, after all the warnings, all the pleas for vigilance and all the new security procedures a plane can still brought out of the sky above New York City, the administration will have an almost impossible task in restoring public confidence.

Airports quiet

But the question remains as to what impact the crash will have. Whatever its causes, it is difficult to call. Immediately after the incident, passengers at Reagan National airport described themselves as "concerned", "shocked" and "horrified".

And they were the ones who actually were flying. Vast numbers of Americans who once flew have refused to return to the skies; the airlines are bleeding money; the airports in general are much quieter.

US air travel: security high, confidence low

Monday's incident will obviously not help. But, so long as terrorism is swiftly ruled out as a cause, it is difficult to see it further harming an industry already in terrible pain.

Flyers are not as confident as they were and they are now no more confident than they might have been. But Americans need to fly, such is the vastness of this country and the far-flung nature of family and business relations.

More difficult to divine is the mood of Americans on the ground; how has another plane falling from the sky shaken people?

Outside New York's fire and police stations the wilting flowers and dirty candles that made up tributes to the fallen are beginning to be cleared away. Now new tributes to those who died are piled up.

No panic

But it is a mistake to underestimate Americans. Despite cultural stereotypes they are not naturally hysterical; there was no panic during the recent posting of anthrax bacteria or the deaths that followed - concern, certainly, fear as well, but no panic.

And they know that accidents happen and will continue to happen. Whilst yesterday's events have brought gloom to an already grieving country, many Americans believe that life must and will go on.