1.  They urge caution--a number of false alarms have been raised about previous plane crash investigations.

2.  Previous U.S. planes were part of the humanitarian airlift managed by the U.N. refugee agency, or airdrops flown from Germany.

3.  Previous U.S. planes were part of the humanitarian airlift managed by UNHCR, or airdrops flown from Germany.

4.  Thousands of onlookers joined them, most drawn by curiosity, although in previous Andean plane crashes there has been looting.

5.  The worst previous plane accident in Nigeria was also at Kano.

6.  The worst previous Nigerian plane accident was also at Kano.