Cover Image


View/Hide Left Panel


To fully appreciate the events that day, we must understand their rapidity and scale. Table 1 provides a chronology. Within 18 minutes, planes struck each of the two World Trade Center towers in New York. Eighteen minutes after United Airlines flight 175 struck the south tower, all bridges and tunnels into the New York City area were closed. Sixty-two minutes after the south tower was struck, it collapsed, killing those still trapped inside as well as first responders who arrived to deal with the impact of American Airlines flight 11 into the north tower. The Port Authority Trans Hudson (PATH) line station was partially crushed by the collapse of the south tower. Twenty-three minutes later, the north tower collapsed.

The collapse of the twin towers caused collateral damage of varying degrees to 29 million sq ft of office space in lower Manhattan; started fires in nearby structures; and caused major portions of the transportation, power, telecommuni-

TABLE 1 Chronology of Events of September 11, 2001

Time (EDT)


8:46 a.m.

A hijacked passenger jet, American Airlines flight 11 from Boston, Massachusetts, crashes into the north tower of the World Trade Center, tearing a gaping hole and setting the building afire.

9:03 a.m.

A second hijacked airliner, United Airlines flight 175 from Boston, crashes into the south tower of the World Trade Center and explodes.

9:17 a.m.

The Federal Aviation Administration shuts down all New York City area airports.

9:21 a.m.

The Port Authority of New York and New Jersey orders all bridges and tunnels in the New York area closed.

9:40 a.m.

The FAA halts all flight operations at U.S. airports, the first time in U.S. history that air traffic nationwide has been halted.

9:43 a.m.

American Airlines flight 77 crashes into the Pentagon.

10:05 a.m.

The south tower of the World Trade Center collapses, plummeting into the streets below. A massive cloud of dust and debris forms and slowly drifts away from the building.

10:10 a.m.

A portion of the Pentagon collapses. United Airlines flight 93, also hijacked, crashes in Somerset County, Pennsylvania, southeast of Pittsburgh.

10:24 a.m.

The FAA reports all inbound transatlantic aircraft flying into the United States are being diverted to Canada.

10:28 a.m.

The World Trade Center’s north tower collapses from the top down as if it were being peeled apart, releasing a tremendous cloud of debris and smoke.

11:02 a.m.

New York City Mayor Rudolph Giuliani urges New Yorkers to stay at home and orders an evacuation of the area south of Canal Street.

2:49 p.m.

Subway and bus service is partially restored in New York City.

4:10 p.m.

Building 7 of the World Trade Center complex is reported on fire.

5:20 p.m.

The 47-story Building 7 of the World Trade Center complex collapses. The evacuated building was damaged when the twin towers across the street collapsed earlier in the day. Other nearby buildings in the area remain ablaze.

The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement