In the worst terrorist attack ever on U.S. soil, hijackers crashed passenger planes into the World Trade Center in New York, toppling the 110-story twin towers, killing all aboard the jets and an unknown number on the ground.
Another passenger plane crashed into the Pentagon outside Washington, leaving a gaping gash in the nation's hub of military power, killing all on board the aircraft and more on the ground. Within the hour, a fourth airliner went down near Pittsburgh, killing everyone aboard.
There were no immediate details available on casualties, but thousands of people work in the affected buildings — 50,000 in the World Trade Center alone. Hundreds of people were in local hospitals. New York Mayor Rudolph Giuliani said hundreds of firefighters were feared dead and the death count could "go into the thousands."
Giuliani also said he believed some victims were still alive underneath the rubble but firefighters were unable to reach them because of the smoke, the heat of the rubble and the amount of debris.
With a black smoke billowing over the area where the World Trade Center towers once stood, city officials also said the dead were buried under several feet of soot and debris and that machines would be need to lift some of the rubble to help firefighters with the body recovery.
"It's tough. … we should hug one another and give thanks that we're all here," Giuliani said. "Tomorrow is another day. New York is still here, and we will rebuild and be stronger than ever."
There were reports that officials at Port Authority of New York and New Jersey had stopped a van at the George Washington Bridge that may have contained explosives, but Port Authority and Fort Lee, N.J., police said those claims were untrue.
Meanwhile at the Pentagon, the smell of smoke, jet fuel and gas was still rising as some of the dead lay outside the damaged building. The entire area was deserted of civilian and military employees, but dozens of emergency personnel were stationed outside the building doing triage on the wounded and searching for bodies still underneath the debris.
As Pentagon officials identified the dead, they began contacting next of kin. The chief of the Arlington, Va., Fire Department estimated that were between 100 and 800 people dead at Pentagon.
Washington, D.C., Police Chief Charles Ramsey said security in the area would be no longer "business as usual" and that officials were still assessing whether roads will continue to be closed Wednesday. Ramsey's department also recommended that next month's meeting between the World Bank and the International Monetary Fund in Washington be canceled or postponed.
In an address to the nation tonight, President Bush vowed that the terrorists would be brought to justice.
"The functions of our government will continue without interruption," Bush said from the White House. "Our financial institutions remain strong. The American economy will be open for business as well. We have a full resolution to find those responsible for this evil act and bring them to justice. We will make no distinction between terrorists who committed these acts and those who harbor them."
President Bush was meeting with his National Security Council staff tonight and was expected to remain at White House until Wednesday morning.