NEW YORK - Mounting an audacious attack against the United States, terrorists crashed two hijacked airliners into the World Trade Center and brought down the twin 110-story towers Tuesday morning. A jetliner also slammed into the Pentagon as the seat of government itself came under attack.
Hundreds were apparently killed aboard the jets, and untold numbers were feared dead in the rubble. Thousands were injured in New York alone.
A fourth jetliner, also apparently hijacked, crashed in Pennsylvania as the part of the closely timed series of attacks.
President Bush ordered a full-scale investigation to "hunt down the folks who committed this act."
Authorities were still trying to evacuate those who work in the twin towers when the glass-and-steel skyscrapers came down in a thunderous roar within about 90 minutes after the attacks, which took place 18 minutes apart around 9 a.m. Many people were feared trapped. About 50,000 people work at the Trade Center and tens of thousands of others visit each day.
Officials said the Trade Center apparently was hit by two Los Angeles-bound jetliners that had been hijacked after taking off from Boston 15 minutes apart with a total of 157 people: United Flight 175, with 65 people on board, and American Flight 11, with 92 people aboard.
The Pentagon was hit by American Flight 77, which was seized while carrying 64 people from Washington to Los Angeles, according to law enforcement officials, speaking on condition of anonymity.
And in Pennsylvania, United Flight 93, a Boeing 757 en route from Newark, N.J., to San Francisco, crashed about 80 miles southeast of Pittsburgh with 45 people aboard. A Virginia congressman, Rep. James Moran, said the intended target of the plane was apparently Camp David, the presidential retreat in Maryland, 85 miles away from the crash site.
Altogether, the four planes carried 266 people. There was no word on any survivors.
At the Trade Center, people on fire leaped from the windows to certain death, including a man and a woman holding hands. Some jumped from as high as the 80th floor as the planes exploded into fireballs. People on the ground screamed and dived for cover as debris from the 1,250-foot towers rained down. Dazed office workers covered in gray ash wandered around like ghosts, weeping, trying to make sense of what happened.
Donald Burns, 34, who had been at a meeting on the 82nd floor, saw four severely burned people on the stairwell. "I tried to help them but they didn't want anyone to touch them. The fire had melted their skin. Their clothes were tattered," he said.
"People were screaming, falling and jumping out of the windows," from high in the sky, said Jennifer Brickhouse, 34, of Union, N.J., who was going up the escalator into the World Trade Center.
Within the hour after the attack in New York, the Pentagon took a direct, devastating hit from a plane. The fiery crash collapsed one side of the five-sided structure.
Speculation about the attack quickly focused on terrorist fugitive Osama bin Laden.
"No one has been ruled out, but our initial feeling is that this is the work of bin Laden," said a high-ranking federal law enforcement official who spoke on condition of anonymity. "He is top of our list at this point."
"This is perhaps the most audacious terrorist attack that's ever taken place in the world," said Chris Yates, an aviation expert at Jane's Transport in London. "It takes a logistics operation from the terror group involved that is second to none. Only a very small handful of terror groups is on that list. … I would name at the top of the list Osama bin Laden."
The president put the military on its highest level of alert. Authorities in Washington immediately called out troops, including an infantry regiment, and the Navy sent aircraft carriers and guided missile destroyers to New York and Washington.
The White House, the Pentagon and the Capitol were evacuated along with other federal buildings in Washington and New York. The president was taken to Offutt Air Force Base in Nebraska, headquarters for the Strategic Air Command, the nation's nuclear strike force, the White House said. Later, he headed back to Washington.
The U.S. and Canadian borders were sealed, security was tightened at naval installations and other strategic points, and all commercial air traffic across the country was halted until at least noon on Wednesday.
"This is the second Pearl Harbor. I don't think that I overstate it," said Sen. Chuck Hagel, R-Neb. The Dec. 7, 1941, Japanese attack on Pearl Harbor killed nearly 2,400 people and drew the United States into World War II.
Sen. John McCain, R-Ariz., said: "These attacks clearly constitute an act of war."
In June, a U.S. judge had set Wednesday as the sentencing date for a bin Laden associate for his role in the 1998 bombing of a U.S. embassy in Tanzania that killed 213 people. The sentencing had been set for the federal courthouse near the World Trade Center. But the sentencing had been postponed some time ago without being rescheduled.
Afghanistan's hardline Taliban rulers condemned the attacks and rejected suggestions that bin Laden was behind them, saying he does not have the means to carry out such well-orchestrated attacks. Bin Laden has been given asylum in Afghanistan.
Abdel-Bari Atwan, editor of the Al-Quds al-Arabi newspaper, said he received a warning from Islamic fundamentalists close to bin Laden, but did not take the threat seriously. "They said it would be a huge and unprecedented attack but they did not specify," Atwan said in a telephone interview in London.
In the West Bank city of Nablus, thousands of Palestinians celebrated the attacks, chanting "God is Great" and handing out candy.
"Freedom itself was attacked this morning by a faceless coward and freedom will be defended," Bush said form a tightly guarded air base in Louisiana.
In New York, the downtown area was cordoned off and a rescue effort was under way. Hundreds of volunteers and medical workers converged on triage centers, offering help and blood. Paramedics waiting to be sent into the rubble were told that "once the smoke clears, it's going to be massive bodies," said Brian Stark, a former Navy paramedic who volunteered to help.
He said the paramedics had been told that hundreds of police and firefighters were missing from the ranks of those sent in to respond to the first crash.
Mayor Rudolph Giuliani said 2,100 people were injured - 1,500 "walking wounded" who were taken to New Jersey, and 600 others who were taken to area hospitals, 150 of them in critical condition. It could take weeks to dig through the rubble for victims. About 100 people were reported killed or injured in the Pentagon.
"I have a sense it's a horrendous number of lives lost," Giuliani said. "Right now we have to focus on saving as many lives as possible."
By evening, huge clouds of smoke still billowed from the ruins, obscuring much of the skyline. A burning 47-story part of the World Trade Center complex collapsed just before nightfall. The building had already been evacuated.
The two planes blasted fiery, gaping holes in the upper floors of one of New York's most famous landmarks and rained debris on the streets. About an hour later, the southern tower collapsed with a roar and a huge cloud of smoke; the other tower fell about a half-hour after that, covering lower Manhattan in heaps of gray rubble and broken glass.
On the street, a crowd mobbed a man at a pay phone, screaming at him to get off the phone so that they could call relatives. Dust and dirt flew everywhere. Ash was 2 to 3 inches deep in places.
John Axisa, who was getting off a commuter train to the World Trade Center, said he saw "bodies falling out" of the building. He said he ran outside, and watched people jump out of the first building. Then there was a second explosion, and he felt heat on the back of neck.
David Reck was handing out literature for a candidate for public advocate a few blocks away when he saw a jet come in "very low, and then it made a slight twist and dove into the building."
People ran down the stairs in panic and fled the building. Thousands of pieces of what appeared to be office paper drifted over Brooklyn, about three miles away.
Several subway lines were immediately shut down. Trading on Wall Street was suspended. New York's mayoral primary election Tuesday was postponed. All bridges and tunnels into Manhattan were closed.
The death toll on the crashed planes alone could surpass that of the Oklahoma City bombing on April 19, 1995, which claimed 168 lives in what was the deadliest act of terrorism on U.S. soil.
Evacuations were ordered at the United Nations in New York and at the Sears Tower in Chicago. Los Angeles mobilized its anti-terrorism division. Walt Disney World in Orlando, Fla., was evacuated, and Hoover Dam on the Arizona-Nevada line was closed to visitors. Security was tightened along the 800-mile trans-Alaska oil pipeline.
Terrorists blew up a truck bomb in the basement of the World Trade Center in February 1993, killing six people and injuring more than 1,000 others.
"It's just sick. It just shows how vulnerable we really are," Keith Meyers, 39, said in Columbus, Ohio. "It kind of makes you want to go home and spend time with your family. It puts everything in perspective," Meyers said. He said he called to check in with his wife. They have two young children.
In 1945, an Army Air Corps B-25, a twin-engine bomber, crashed into the 79th floor of the Empire State Building in dense fog.
In Florida, Bush was reading to children in a classroom at 9:05 a.m. when his chief of staff, Andrew Card, whispered into his ear. The president briefly turned somber before he resumed reading. He addressed the tragedy about a half-hour later.
Before the crash in Pennsylvania, an emergency dispatcher in Westmoreland County, Pa., received a cell phone call at 9:58 a.m. from a man who said he was a passenger locked in the bathroom of United Flight 93, said dispatch supervisor Glenn Cramer.
"We are being hijacked, we are being hijacked!" Cramer quoted the man as saying. The man told dispatchers the plane "was going down. He heard some sort of explosion and saw white smoke coming from the plane and we lost contact with him," Cramer said.