According to the September 11 Commission, Khalid Sheikh Mohammed envisioned a hijacking of twelve airplanes on both the East and West coasts, and for eleven of them to be crashed into the World Trade Center and the Empire State Building in New York City; The Pentagon in Arlington, Virginia; the Prudential Tower in Boston, Massachusetts; the White House and the United States Capitol in Washington, D.C.; the Willis Tower (then Sears Tower) in Chicago, Illinois; the U.S. Bank Tower (then Library Tower) in Los Angeles, California; the Transamerica Pyramid in San Francisco, California; and the Columbia Center in Seattle, Washington.