United Airlines concerned about fourth plane

One of the planes that crashed into the Trade Center was American Airlines

American Airlines issued a statement saying it had "lost" two aircraft – Flight 11, with 92 people aboard, and Flight 77 from Washington to Los Angeles, carrying 64 people.

In Pennsylvania, United Airlines Flight 93, a Boeing 757 en route from Newark, N.J., to San Francisco, crashed about 80 miles southeast of Pittsburgh.

The fate of those aboard was not immediately known and it was not clear if the crash was related to the disasters elsewhere.

In a statement, the airline also said it was deeply concerned about another

plane, Flight 175, a Boeing 767 bound from Boston to Los Angeles.