71.   Both died when the tower collapsed.

72.   Burns had been setting up a command post when the tower collapsed.

73.   But the towers collapsed, and Lim, a Port Authority of New York and New Jersey officer, was trapped in the debris for several hours.

74.   But those are the words they are using when they remember that thousands of others got out alive before the towers collapsed.

75.   Ever since the towers collapsed, the spot has been likened to a war zone.

76.   He did not know the twin towers had collapsed until he was safely in the hospital, he said.

77.   He had been setting up a command post when the tower collapsed.

78.   He asked campaign supporters for a moment of silence in honor of the people still missing since the twin towers collapsed.

79.   He told the British Broadcasting Corp. the interview questioned why the twin towers collapsed the way they did.

80.   Independent engineers discovered the structural problems after a stadium light tower collapsed last year and killed an ironworker.