Terrorists attacked New York and Washington D.C. in an unprecedented widespread scale on Tuesday morning, destroying the twin towers of the World Trade Center and the Pentagon in Washington by three airplane, with a fourth plane crashed in Pennsylvania.
In the first attack, a plane hit the north tower of the World Trade Center in Manhattan around 8:45 am (1345gmt) local time, followed by another plane into the second tower about 20 minutes later.
Both towers collapsed, no figure of either casualties or injuries were available - an average 15,000 persons, including tourists, visited the towers.
American Airlines confirmed that it lost two planes in "tragic accidents".
Flight 11 from Boston with 81 passengers and 11 crew aboard and Flight 77 from Washington Dulles airport with 58 passengers and six crew aboard.
Both planes were en route to Los Angeles.
About an hour later, a plane crashed into the Pentagon, part of which later collapsed.
United Airlines Flight 93 airliner headed from Newark, New Jersey to San Francisco, crashed near Somerset, Pennsylvania.
Police said initial reports indicated no survivors.
It was not known if this was connected to the attacks.
United also said it was "deeply concerned" about Flight 175 from Boston to Los Angeles.
The Pentagon, the White House, the State Department, the Justice Department, the Capitol, the CIA and all other government buildings in Washington evacuated.