1.  An American plane out of Dulles and a United plane out of Newark, along with the two flights from Logan Airport here, were hijacked on Tuesday.

2.  One American and one United plane hit the World Trade Center, while another United airplane crashed southeast of Pittsburgh.

3.  This has been repeatedly cited as the strongest evidence of possible insider trading in this country, since only American and United planes were hijacked.

4.  United Airlines confirms second United plane crashing, location not given.

5.  Wilson said the United plane may have hit clear-air turbulence, a rarer, more severe phenomenon which cannot be detected in advance.