11.   Analysts say any number of factors could be responsible, including bad weather, poor judgment or mechanical failure.

12.   And while the preliminary word was that the crash bore the characteristics of mechanical failure, few words could offer much solace to a city still trying to recover.

13.   As that evidence has eluded investigators, some officials at the National Transportation Safety Board have begun a re-examination of the possibility of a mechanical failure.

14.   Asked if that meant the evidence was suggesting mechanical failure, Kallstrom said he would not comment.

15.   Aviation experts say they cannot exclude mechanical failure, but they cannot come up with a scenario for a mechanical problem that would suddenly destroy a plane.

16.   Because there is no evidence of mechanical failure, an FBI official replied.

17.   Ben-Eliahu said there was no indication of mechanical failure and the flights were on schedule.

18.   Besides, they say, the plane could have been hit by a missile or rocket, and a few still insist that mechanical failure is an outside possibility.

19.   Boeing says it has essentially ruled out the possibility that mechanical failure brought the plane down.

20.   A couple of hundred pounds of newly dredged wreckage was being examined Wednesday for any indications that an explosive device or mechanical failure had destroyed the jet.