FBI Director Robert Mueller says the agency has identified most of the hijackers responsible for Tuesday’s devastating terrorist attacks and many of their associates, but that no arrests have been made. The attacks leveled New York’s World Trade Center towers and damaged the Pentagon. Thousands are feared dead.

“We have in the last 24 hours taken the [flight] manifests and used them as an evidentiary base,” Mueller told a press conference Wednesday afternoon, “and have talked to many of the families of the victims, and have successfully, I believe, identified many of the hijackers on each of the four flights.”

“We also have identified through a number of leads, principally at the cities of origin, a number of individuals who we believe may have had something to do with the hijackings, and we are pursuing those leads aggressively,” Mueller continued.

Mueller denied reports that suspects arrested in Boston, and others taken into custody in Florida, were being held in connection with the case.

“There have been occasions where we have interviewed individuals and come to find that the individual is out of status,” Mueller said, “and that individual has been detained on an immigration hold, but there has been no arrest relating to these hijackings at this point.”

Mueller said the FBI was pursuing leads in Providence, R.I., as well as Boston and Florida.

At the same press conference, Attorney General John Ashcroft confirmed earlier reports that each of the four planes that crashed Tuesday was commandeered by a team of three to six hijackers using knives and box-cutters, and at times making bomb threats. Ashcroft said there is credible information that the White House and Air Force One were both targeted Tuesday.

Four planes were hijacked Tuesday. Two of them, both originating in Boston, crashed into the World Trade Center in New York, destroying those landmark towers. Another, which took off from Washington Dulles airport, slammed into the Pentagon near the nation’s capital. A fourth plane, originating in Newark, N.J., crashed in rural Pennsylvania, apparently missing its target — speculated by authorities to be either the presidential retreat in Maryland at Camp David, Edwards Air Force Base, the White House or the Capitol.

The presidential residence also may have been the target of another plane, perhaps United Flight 93, destined for San Francisco from Newark, N.J., which crashed in a field in rural Pennsylvania. At a separate press conference, White House spokesman Ari Fleischer said, “We have real and credible information that the plane that hit the Pentagon was intended to hit the White House.” Fleischer said the threats to the White House and Air Force One were the reason President Bush flew to Louisiana and Nebraska before returning to Washington Tuesday. Bush began his day in Florida.

There is also indication that Flight 93 may have missed its target because passengers on board confronted the hijackers. A number of passengers on board called relatives from the flight, and indicated that the male passengers on board were going to try to wrest control of the plane from the hijackers after the passengers heard of the attacks at the World Trade Center.

Two hundred sixty-six people died on the downed planes, and Mayor Guiliani said that he expected “thousands” to be found on the ground in the buildings. New York officials said that more than 250 firefighters and police officers were missing and feared dead. There were reports Wednesday afternoon that four or five firefighters had been located alive in the rubble, but hadn’t been rescued yet.

As rescuers vainly attempted to reach any further survivors, damaged buildings surrounding the World Trade Center continued to collapse. The remaining portion of the southern tower disintegrated at 5:30 p.m. EDT, and the area was swiftly evacuated as the 54-story One Liberty Plaza — home to the headquarters of the NASDAQ, just to the east of the World Trade Center — also partially collapsed.

In the day and a half since the attack, government and law enforcement officials have said that early evidence points to Saudi exile Osama bin Laden, a billionaire terrorist leader who was suspected of masterminding the U.S. embassy bombings in Africa and considers himself a declared enemy of the United States. But officials have refused to rule out other possibilities. Bin Laden is thought to be living Afghanistan under the protection of that country’s fundamentalist Taliban rulers.

As what was expected to be the largest law enforcement investigation in American history swung into full gear Wednesday, police and the FBI took several people into custody in Boston and South Florida in connection with the terrorist attacks.

The Boston Globe reported that three people had been arrested after a fully-armed tactical squad of Boston police and FBI entered the Westin Hotel in Copley Square early Wednesday afternoon. Ambulances and bomb squad trucks stood by outside the hotel as a crowd gathered and TV networks beamed live pictures. There was a report that one of the suspects was injured. A stretcher was seen being carried into the hotel.

The Boston Herald reported in its Wednesday editions that authorities had seized a rental car in a Logan airport garage that contained Arabic-language flight training manuals. Passports of five suspects identified by Massachusetts authorities were traced to the United Arab Emirates, the Herald’s source said. Two of the men were brothers, and one of the brothers was a trained pilot.

Authorities were led to the car, which was rented from National Car Rental, by a man who got into an altercation with several Arab men as they were parking their car, sources told the Herald. The man called state police after his flight landed in another state and he learned about the hijacking tragedy.

The paper quoted Robert Fitzpatrick, a former second-in-command in the FBI’s Boston office, saying that Boston appears to have been the staging area for the attack on New York and that the hijackers most likely had help from others who may still be in Boston.

There’s a terrorist cell operating out of Boston,” Fitzpatrick said. “They had to have support, they had to have people on the ground, in Boston, supporting them.”

A flight manifest from one of the ill-fated flights included the name of a suspected bin Laden supporter. And U.S. intelligence intercepted communications between bin Laden supporters discussing Tuesday’s attacks, Hatch told the Associated Press.

Also, a bomb squad searched the cargo hold of a Continental Airlines jet at Daytona International Airport. Fox News reported that some of the terrorists may have received flight training at Embry-Riddle Aeronautical University in Daytona Beach, but it was not known why the plane was being searched.

In Florida Wednesday, the FBI and Coral Gables police entered the home of a suspected hijacker, Mohammad Atta, and issued a “BOLO,” or “be on the lookout,” for two cars. The FBI confirms it has people in custody in Florida, but won’t say whether anyone was taken out of the Coral Gables home. FBI officials have also been in contact with the Huffman Aviation flight school in Venice regarding one of the school’s students.

A southwest Florida man said FBI agents investigating the terrorist attacks told him that two men who stayed with him while getting flight training last year were involved in Tuesday’s attacks. Charlie Voss, a former employee at Huffman Aviation in Venice, said FBI agents who interviewed him at his home told him that a car found at Boston’s Logan International Airport was registered to the two men. The car had Arabic-language flight training manuals inside. Voss said one of the men who stayed at the house in July 2000 was named Mohamed Atta. He said he knew the other man only by the name of Marwan.

In Hamburg, Germany, police searched an apartment at the request of the FBI, according to CNN. The apartment was empty, but a police spokesman said five people of “apparently Arab descent” had been using it until February.

Meanwhile, leaders around the world sent their regrets, and Fleischer said President Bush “is very heartened by the world reaction.” The president had spoken to Russian President Vladimir Putin twice, said Fleischer, and “The two presidents said they would work closely together.”

Secretary of State Colin Powell, speaking at the Pentagon Wednesday, said he was trying to build a worldwide coalition against terrorism, but gave no specifics. “When you’re attacked by a terrorist and you know who the terrorist is, you should respond,” Powell said. The secretary said military action was a possibility, but announced no plans for a strike. He said NATO allies may or may not participate in any attack, but would be obligated to assist the United States should it invoke Article 5 of the alliance treaty and attack the suspected terrorists or those who harbored them.

Secretary of Defense Donald Rumsfeld also engaged in some saber-rattling, saying, “We are in a sense seeing the definition of a new battlefield in the world.” Asked what kind of resolve the United States had to respond to those responsible for Tuesday’s attacks, Rumsfeld said, “I guess I’m old-fashioned. I’m inclined to think that if you’re going to cock it, you throw it, and you don’t talk about it a lot.”

In a strange interlude at his Pentagon press conference, Rumsfeld spoke at length about classified information being leaked to people who aren’t cleared to have it. He said the relaxed tensions that came with the end of the Cold War have led to more such leaks, hampering investigations such as the current one and putting uniformed personnel in danger, but he gave no specifics.

Asked if sloppy handling of classified information played some role in Tuesday’s attacks, Rumsfeld paused, then said, “Not to my knowledge. It is an issue that I think, however, needs to be elevated and looked at.” When reporters asked if such leaks had been a factor in the aftermath of the attacks, Rumsfeld snapped, “It has been happening daily,” and left the podium.

Conservative pundits began rumbling about retaliation, some sounding eager to see the U.S. unleash its arsenal without waiting for all the evidence. When CNN’s Judy Woodruff asked former drug czar Bill Bennett if there needed to be a “threshhold of evidence” for the United States to take military action, Bennett said yes, we should be “pretty confident” that we knew who the perpetrators were.

The Federal Aviation Administration prepared to allow the nation’s grounded civilian air industry to resume operations sometime Wednesday, but officials didn’t know when airlines would be allowed to begin flying again, and by late afternoon Wednesday there was no word of a timetable. Commercial air traffic isn’t expected to resume to normal levels until late Thursday at the earliest.

FAA spokesman Les Dorr said people should not expect all flights to resume normal travel, since many planes are at the wrong airports. “I think it is fair to say there is not going to be a mass exodus of planes and passengers that have been on the ground because some of the airlines have airplanes that are literally in the wrong place to fly their schedules,” Dorr said. “Passengers should expect to have to devote more time to the check-in process.”

When flights resume, passengers won’t be able to check their bags at the curb, nor will they be allowed to bring plastic knives on board. They will also be subjected to random checks, they will see more uniformed security and they should arrive at airports even earlier than previously considered appropriate.

At the Pentagon and the World Trade Center, agents sifted through the rubble. President Bush, speaking to his Cabinet at the White House, called the attacks “an act of war,” words echoed throughout the day at the Capitol Wednesday as members of both houses of Congress spoke about the attacks.

At the Pentagon, 80 bodies were pulled from the wreckage, and Pentagon spokespeople said Wednesday that no more survivors were expected to be found. Arlington, Va., fire officials involved in the search and rescue estimated that 200 or more people may have died.

“The FBI evidence recovery team has found parts of the fuselage outside” the Pentagon, Fairfax County chief Michael Tamillow said Wednesday. “As we go in we’re now identifying smaller parts of the plane. Everyone is looking for the black box recorders.” Those recorders could contain conversations from the cockpits of the doomed planes.

“The area of the Pentagon where the aircraft struck and burned sustained catastrophic damage. Anyone who might have survived the initial impact and collapse could not have survived the fire that followed,” the Defense Department said in a written statement.

In New York, Mayor Rudy Giuliani met the press throughout the day as rescue workers continued the grim task of sifting through mountains of dust and rubble in hopes of finding anyone still alive. As of Wednesday morning, nine people, all of them firefighters or police officers, had been rescued. Giuliani said another woman had been pulled out Wednesday and taken to a hospital. There was also a report Wednesday afternoon that a handful of firefighters had been found alive, but had yet to be rescued.

The mayor asked New Yorkers to do as much as possible to return to a normal life, to “show that you’re not afraid.” He said there was only one incident of looting Tuesday night, but also urged people not to turn on each other.

“We’ve had a few, not many, but we’ve had a few incidents that appear to have been directed against people because they may have been regarded as Arab or Asian or Indian or whatever,” Giuliani said. “Nobody should attack anyone else.”

Giuliani said he hoped the stock exchanges, which were closed Wednesday, would open Thursday. But the Associated Press reported late in the afternoon that the New York Stock Exchange would not open before Friday, and possibly not until Monday, making this suspension of scheduled trading the longest in the history of the exchange.

Con Edison said the crashes at the World Trade Center knocked out two power substations, leaving 12,000 customers in lower Manhattan without electricity.

President Bush, speaking to the nation Tuesday night, vowed to “find those responsible and bring them to justice.” In the second Oval Office address of his presidency, Bush said the United States would retaliate against “those behind these evil acts,” and any country that harbors them. “Today, our nation saw evil,” he said.

Bush spoke to his Cabinet before television cameras Wednesday morning, calling the attacks “an act of war” and saying there are no safe harbors for terrorists.

Dozens of United Nations employees evacuated the capital city of Kabul, Afghanistan, and the mothers of two jailed Americans also prepared to leave Wednesday. The U.N. sent emergency flights to transport all 80 of its employees to neighboring Pakistan. U.N. spokeswoman Marie Heuze in Geneva called the withdrawals precautionary, but declined to say whether the United Nations feared a possible reprisal in Afghanistan by the U.S. military.

Though life in the United States began to return to normal Wednesday, many schools and businesses remained closed along with the nation’s airlines. Sporting events scheduled for the weekend, including many college football games, began to be cancelled, and major league baseball postponed its games for the second straight day, an unprecedented move. The National Football League was still considering whether to postpone Sunday’s games.

The Associated Press contributed to this story.

The release party for “Season of the Witch” will be a celebration of the San Francisco values of social tolerance and experimentation, as explored in David Talbot’s new book. This event will feature music and art of the 1967-‘82 era as well as speakers recounting some of the wild stories that defined this explosive time. Guests include director Oliver Stone, who will discuss how films like “The Doors” channeled the demonic energy of the period, and how his love for the San Francisco 49ers was reflected in “Any Given Sunday.” Other special guests include Scrumbly Koldewyn and Fayette Hauser of the infamous drag queen troupe the Cockettes; Peter Lewis of the legendary band Moby Grape; activist Cleve Jones; and other political, sports and literary luminaries.

Salon has always believed in not just truth, but beauty. Our original design back in 1995 – a clean, art deco look created by Salon’s first art director, Mignon Khargie – immediately set Salon apart. Now Salon is once again separating itself from the cookie-cutter digital clutter that defines too much of the Web with a bold and striking new design.

We asked designer Kelly Frankeny to create a news tabloid as imagined by Coco Chanel. Frankeny — a globetrotting designer who is often dropping into beleaguered democracies in Africa and Latin America to work her wonders for embattled newspapers – responded to our challenge with a sophisticated and dynamic design. A brilliant and sassy blond Texan, she has created a new Salon as big as her personality. And yes, while invoking the brassy urgency of a news tabloid, the new design also conveys the elegance of the House of Chanel. Both Frankeny and the new Salon know how to use red lipstick and a simple black dress for maximum effect.

As winter thaws, the hot spots of the Occupy movement are seeing the first ripples of resurgence. From New York to Oakland, Calif., crowds are returning to the streets, but will the plan for a May 1 General Strike spark an American Spring or will the movement splinter and fade into Tea Party-like irrelevance? Watch the Salon webcast with Occupy correspondent Natasha Lennard to hear her thoughts on these issues:

To participate in upcoming Salon webcasts with staff and friends, join the Salon Core community.

Salon has covered the Trayvon Martin killing relentlessly, but none of our coverage has struck a nerve like the article “Is My Son the Next Trayvon?” by the chief operating officer of Salon Studio, Quincy McCoy. As a black man who escaped the rough neighborhoods of his youth to provide a better life for his child, Quincy’s article conveyed the constant anxiety suffered by all black parents — regardless of class.

Quincy recently hosted an online conversation on the epidemic of violence against young black men. Here is the full video of that discussion:

To participate in Salon’s webcasts with staff and friends, join the Salon Core community.

Two years after the president signed it into law, Obamacare is beginning to have a big impact: Millions more young adults are insured; prescription costs for the elderly are on the decline; and children with preexisting conditions can no longer be denied coverage. Yet, as Andrew Leonard detailed on Tuesday, it’s at this very moment when the legislation is starting to extend coverage and reduce costs that the Supreme Court seems determined to destroy it.

As the justices debate constitutionality of the legislation, we want to know how the law is affecting regular Americans. Has the Affordable Care Act changed you or your family’s healthcare experience?

Blog about it on Open Salon – and we may feature your story on Salon.