World Trade Center New York City

As 19 hijackers made their way along the concourses at three East Coast airports on Sept. 11, bent on executing the deadliest terrorist attack in history, they were subjecting the U.S. aviation security system to its most critical test. At almost every step along the way, the system posed no challenge to the terrorists--not to their ability to purchase tickets, to pass security checkpoints while carrying knives and cutting implements nor to board aircraft.

The head of the foundation building the World Trade Center memorial told supporters it's "essential" that it open by Sept. 11, 2011, the 10th anniversary of the attacks. Joe Daniels, president of the National Sept. 11 Memorial and Museum, said in a letter that despite a report that the project could not be finished in time, it must be. "While aggressive, we believe it is both possible and essential that the memorial be open to the public by the 10th anniversary of the 9/11 attacks," Daniels wrote.

As dozens of firefighters stop in front of the casket and mourn their lost friend, the phone in the offices of Thomas F. Dalton Funeral Home quietly rings. Another family, with another missing loved one, is on the line. It's the fifth call the staff has taken Wednesday. "It's incredibly busy for everyone right now," said funeral home official Beth Dalton-Costello. "And none of us knows how to handle it."

The controversial rebuilding at the World Trade Center site will be costlier and even further delayed than projected, the Port Authority of New York and New Jersey said in a report released Monday. "The schedule and cost estimates of the rebuilding effort that have been communicated to the public are not realistic," wrote Chris Ward, executive director of the Port Authority, which owns the site and is responsible for the biggest projects on it.

The man walks into the bar, shakes hands with his friends, orders a beer. He looks like every other man in the place, but he's different, and everyone knows it. They try not to stare. Seven hours later, the man's friends are gone, but the man is still standing in the same spot at the bar, drinking, talking. No one needs to ask why. The whole town knows the man's son died in the World Trade Center, along with nearly 50 other people who hailed from here. His son boarded the 5:43 a.m.

Angry Democrats called for Ohio Republicans to pull a TV spot using images of the destroyed World Trade Center and New York City's ground zero area in an ad against Ohio Democratic congressional candidate Tim Ryan, calling it "disrespectful" and "a new low." The political ad is believed to be the first in the country to use images of the destroyed towers, where nearly 3,000 people died in the terrorist attacks of Sept. 11, 2001, in a negative political ad, Ryan said.

He was last in the line moving up the ramp into a waiting C-130 at Tan Son Nhut air base--a tall, husky man with an open Midwestern face who was about to step into history. It was March 29, 1973, in Saigon. And Master Sgt. Max Beilke was officially designated as the last American combat soldier to leave Vietnam. He had survived two wars, Korea and Vietnam. Now he was going home to his family in Minnesota.

FBI and CIA officials were advised in August that as many as 200 terrorists were slipping into this country and planning "a major assault on the United States," a high-ranking law enforcement official said Wednesday. The advisory was passed on by the Mossad, Israel's intelligence agency. It cautioned that it had picked up indications of a "large-scale target" in the United States and that Americans would be "very vulnerable," the official said. It is not known whether U.S.

In the photo, sweaty young Mike Kehoe is headed up--all the way up a smoky stairwell in the north tower of the World Trade Center just after 9 a.m. on Sept. 11. Kehoe wasn't aware that someone was taking his photograph at that particular moment. He's a firefighter. His mind was focused on hustling all the way up the tower and evacuating office workers. "Civilians," as he calls them.

The terrorists who piloted two planes into the World Trade Center apparently managed--either by careful calculation or evil luck--to have hit the buildings at their weakest spot to cause their disastrous collapse, structural engineers said Tuesday. "It's like hitting someone at the back of the knee," said Nabih Youssef, a structural engineer who heads the Tall Building Council in Los Angeles and is an expert on the design and strength of skyscrapers.

A mangled and twisted metal tower that once broadcast radio and television signals to New York City from the top of the World Trade Center has a new home at the Newseum, Washington's monument to press freedom and other protections of the First Amendment. The tower is just one striking artifact inside the high-tech journalism museum, which also includes large sections of the Berlin Wall, archival video and newspapers dating back nearly 500 years, and thousands of other objects to wow news junkies.

The expanded search for human remains at the former World Trade Center site is over for now. Deputy Mayor Edward Skyler, in a memo to Mayor Michael R. Bloomberg, said that the city Medical Examiner's Office had finished sifting the last of nearly 15,000 cubic yards of material excavated since the renewed search for remains began in October 2006. As a result, the city will shut down a Brooklyn facility it opened last December to analyze the remains.

A second Sept. 11 victim has been identified from human remains found underneath a service road at the World Trade Center site, officials said Friday. More than 400 human bone pieces have been recovered from beneath the service road that carried cleanup and construction trucks in and out of the site after the 2001 terrorist attacks. The search at the spot began in October 2006 when utility workers found more than 80 bones in a manhole in the service road.

Sitting in a chair just after 7:30 a.m., beneath the amber glow of a hallway light, Carol Ashley leans over and ties the laces on an old pair of sneakers. She slips her good shoes into her purse. She knows it will be muddy in the pit. Outside, the sky is gray and rain slaps her windows. Six years ago on a Tuesday morning nothing like this one, Ashley's 25-year-old daughter, Janice, stood in this hallway wearing a taupe dress suit, a silver watch and her great-grandmother's pearl earrings.

Mayor Michael R. Bloomberg and a coalition of relatives of Sept. 11 victims reached a compromise Thursday that would allow them to briefly descend into a small section of the former World Trade Center site, which the city previously had said was unsafe for the annual memorial.

A goal to end the search for human remains at the World Trade Center site by the fall is not realistic, and the effort will continue "for the foreseeable future," a city official said Tuesday. The city medical examiner's office will maintain a presence at the site indefinitely while construction continues in case excavations unearth more human remains, Deputy Mayor Ed Skyler said in a memo to Mayor Michael R. Bloomberg.

In the worst terrorist attack ever against the United States, hijackers struck at the preeminent symbols of the nation's wealth and might Tuesday, flying airliners into the World Trade Center and the Pentagon and killing or injuring thousands of people. As a horrified nation watched on television, the twin towers of the World Trade Center in lower Manhattan collapsed into flaming rubble after two Boeing 767s rammed their upper stories.

Dusty cars sit abandoned in the parking lot near the Highlands Ferry terminal overlooking the New York Harbor, waiting for their commuting owners to return from the World Trade Center and take them home. Home for one of the score of vehicles is Rumson, a tiny, upscale borough that lies about 50 miles south of Manhattan and is filled with bond traders and stock market executives.

Some of the first responders who were exposed to the cocktail of toxins produced at the World Trade Center collapse are developing a form of cancer often seen in much older people, in what one doctor calls the "third wave" of disorders to emerge from the Sept. 11 disaster. Dr. Robin Herbert, codirector of the WTC Medical Monitoring Program at Mount Sinai Hospital in Manhattan, said a wide range of medical conditions had been detected since the program began in 2001, after the Sept. 11 attacks.

Two subjects of a new documentary film joined the chorus of voices determined to focus attention on people who have developed debilitating health problems after breathing toxic dust from the collapsed World Trade Center towers. William Maher and John Graham traveled to Cuba as part of "Sicko," a documentary on the U.S. healthcare system by filmmaker Michael Moore. He brought the men, who had helped clean Lower Manhattan, to Cuba to try to get medical treatment for them at the U.S.