Flight 93

At some point, before the plane reached Cleveland, the hijackers took over the plane, armed with knives and the threat of a bomb.

Around 9:30 a.m., air-traffic controllers in Cleveland heard someone in the cockpit say, "Hey, get out of here!" according to a source close to the investigation.

Then, in what was described as a thick Arabic accent, a voice was heard that appeared to be addressing passengers, even though it was radioed to air-traffic control.

"This is your captain," the man said. "There is a bomb on board. Remain in your seats. We are returning to the airport."

How the hijackers overpowered the pilots remains unclear. One passenger would report in a telephone call that two people lay on the floor in the first-class cabin, either injured or dead. They appeared to be the pilot and co-pilot, he said, relating information from a flight attendant. Another told a friend that two people had their throats slit but didn't identify them. A third saw only one injured.

At least five passengers and flight attendants described the hijackers in their calls in similar terms: three men, wearing red bandannas, one with some sort of box strapped around his waist that he claimed was a bomb. One passenger reported that two of the hijackers were in the cockpit and a third guarded passengers in first-class from behind a curtain.

4th hijacker not seen

None of the callers mentioned a fourth hijacker, although the FBI has identified four men in connection with the hijacking.

Those men are Saeed Alghamdi, Ahmed Ibrahim A. Al Haznawi, Ahmed Alnami and Ziad Samir Jarrah.

It may be that the people who made calls were unable to see the fourth hijacker. Some news reports have suggested one may have already gained access to the cockpit, as a uniformed guest pilot sitting in the spare jump-seat. Or, some terrorism experts suggest, he may have played a role as a "back-up," perhaps remaining unidentified among the other passengers or hiding in the bathroom until he was needed.

A Justice Department spokeswoman said Friday that their "best information" shows that four were involved.

By 9:36 a.m., United Flight 93 had suddenly changed course, according to flight path information provided by Flight Explorer, a firm that supplies real-time radar tracking data, making a U-turn and heading back toward Washington.

Frantic calls begin

In the cabin, passengers frantically began making calls, 23 of them from the seat-back phones alone from 9:31 to 9:53 a.m. Others passed cell phones to people who had been strangers just minutes before.

Why so many people were able to make calls while apparently under guard by hijackers could be that, as one passenger reported, there was no hijacker among the passengers in coach.

Some of the telephone calls were short--no more than a few rushed words of fear or love.

Lauren Grandcolas, flying home to San Rafael, Calif., from her grandmother's funeral, left a message for her husband saying her flight had been hijacked but she was "comfortable, for now."

Linda Gronlund and Joe Deluca, on their way to San Francisco for a vacation together, took turns. She called her sister to say she would miss her. He called his father.

"The plane's been hijacked," he said. "I love you."

Andrew Garcia, an Air National Guard air traffic controller and plane buff, only managed to get out his wife's name, "Dorothy," before his phone went dead.

Other passengers, though, managed to conduct fairly lengthy, even repeated conversations during the plane's final minutes, constructing a jumbled puzzle of what was happening inside the Boeing 757.

Deena Burnett was feeding her three daughters breakfast and watching the news in horror when the telephone rang in her home in San Ramon, Calif.

"Are you OK?" she asked her husband, Tom, 38.

"No," he said. "I'm on the airplane and it's been hijacked."

He told his wife that the hijackers had already stabbed someone. He told her to call the authorities, and he hung up.

When he called back, she was on the line to the FBI. She told him about the World Trade Center, the first he knew of the attack. He paused. "Were they commercial airplanes?" he asked.

Deena Burnett didn't think so. Cargo or private planes, she said.

"Do you know anything else about the planes?" No, she said.

"Do you know who was involved?" Again, she said no.

He told her that the man who was stabbed had died.

The hijackers are talking about running the plane into the ground, he said. Then he said he had to go.

His third call came about 9:41 a.m., shortly after a plane had hit the Pentagon. "OK," he said. "We're going to do something."

In his fourth and final call, just before 10 a.m., Burnett said he was sure the hijackers didn't have a bomb, that he thought they only had knives.

"There's a group of us who are going to do something," he repeated.

Deena Burnett thought about her years of training as a flight attendant, where she was taught to appease hijackers, to meet their demands, to stay in the background. She told her husband to sit down. "Don't draw attention to yourself," she said.

She told him she loved him. She felt he thought he was coming home that night. This was simply a problem that he was going to solve, as he had solved many others.

Takeover plots hatching

As Burnett talked with his wife, three other men who may have joined him in whatever plans were being hatched made calls of their own.

Across the aisle in Seat 4D, Mark Bingham, 31, called his mother. He was so rattled that when Alice Hoglan got on the line, her son told her, "This is Mark Bingham."

His message was brief: The plane had been hijacked by three men and he loved her.

In the rear of the plane, Jeremy Glick, also 31, a sales manager for a Web site firm and former judo champion, called his wife from a seatback phone. He described three Middle Eastern men brandishing knives and a red box.

His wife told him about the attacks at the World Trade Center. He tried to grasp the hijackers' plans--to blow up the plane or fly it into a target?

The passengers had taken a vote among themselves, he said. They had decided to try to take back the plane.

"I told him to go ahead and do it," Lyzbeth Glick said on "Good Morning America. "I trusted his instincts, and I said, `Do what you have to do.' I knew that I thought he could do it."

Details relayed to operator

Beamer, 32, an account manager for Oracle Corp., called a stranger. He picked up a seat-back phone and hit "0," and at 9:45 a.m., he was connected first to a dispatcher for GTE Airfone, and then to Lisa Jefferson, the operator's supervisor.

For 13 minutes, Beamer told Jefferson everything he could, passing along information he gleaned himself as well as from a flight attendant. The passengers remained in their seats, she said he told her, and the flight attendants were forced to sit in the back of the plane.

He told her how much he loved his pregnant wife and two sons, and he asked her to call them. He asked her to say the Lord's Prayer and 23rd Psalm with him.

Moments later, Beamer told Jefferson about the plan, that the passengers were going to run up the long, narrow aisle to the first-class cabin and attack the hijacker there.

"I'm going to have to go out on faith," Beamer said.

He turned to someone else, and he said, "Are you ready?" Then, in the last words Jefferson would hear from him, "OK. Let's roll."

Sandra Bradshaw, the flight attendant, also identified three hijackers when she called her husband in Greensboro, N.C. She had been moved to the back of the plane, she said, but she and other passengers had a plan. They were going to rush their captors; she was boiling water to throw on them.

Another passenger, Elizabeth Wainio, also apparently talked of a plan to rush the hijackers. In a call she made to her stepmother in Baltimore, using the cell phone lent to her by Lauren Grandcolas, she said, "I've got to go now, Mom, they're breaking into the cockpit," according to the mother of another passenger, who said she spoke with family members about the call. Wainio's parents declined comment.

The accounts of these calls--if accurate--would indicate that at least four people were somehow plotting to attack the hijackers. If Beamer's report is accurate, they were seated in different sections of the plane, with Bingham and Burnett up front, while the others were in the back.

It may be there were separate plans to take the plane or that somehow, amid all the telephone calls, chaos and fear, the passengers were able to communicate with each other.

If they did, they may have known they had another pilot among them, Donald Greene, chief executive officer of Safe Flight Instrument Corp. in New York. Greene, according to his family, knew anything and everything about airplanes.

At about 9:54 a.m., the plane started flying erratically. In Oak Brook, Ill., Jefferson heard screams in the background.

Flight plan changes

Two minutes later, the plane's flight plan changed. The destination airport was changed from San Francisco International to Ronald Reagan Washington National Airport. Estimated time of arrival: 10:28 a.m.

At nearly the same moment, from the plane's bathroom, someone called 911, repeating that Flight 93 had been hijacked, that this was not a hoax.

Then, Marion Britton called a longtime friend, Fred Fiumano, at his New York City auto shop.

Britton, crying, told him the plane was turning around. It was going to go down.

"Don't worry about it," Fiumano said, trying desperately to reassure her. "They're only taking you for a ride."

He heard yelling and screaming in the background, and then the phone went dead. He tried to call the cellular phone number back, but no one answered.

A few of the passengers expected they would win the battle. Before Lyzbeth Glick turned over the phone to her father because she couldn't bear to listen anymore, her husband told her, "Hang on the line. I'll be back."

At about 10:03 a.m., a black crater bloomed in the soft earth of a field 80 miles southeast of Pittsburgh.

The wife in California, the father-in-law in New York, the operator in suburban Chicago still held onto their phones.

They held on, waiting and hoping in the silence.

Tribune reporters Douglas Holt, Naftali Bendavid and Dan Mihalopoulos contributed to this report.

Indianapolis High Altitude Air Traffic Control Center coverage area

3) Last tracked location of Flight 77

(flight heads back to D.C. and crashes into Pentagon)

Timeline of Events

7:45 a.m. American Airlines Flight 11 leaves Boston for Los Angeles.

7:58 United Airlines Flight 175 leaves Boston for Los Angeles.

8:01 United Airlines Flight 93 leaves Newark for San Francisco.

8:10 American Airlines Flight 77 leaves Washington for Los Angeles.

8:20 Air trafÞc controllers in New England suspect Flight 11 has been hijacked.

8:40 FAA notifies NEADS (Northeast Air Defense Sector) of NORAD, the military's civil defense system, about Flight 11.

8:43 FAA notifies NEADS about Flight 175.

8:46 American Airlines Flight 11 hits the World Trade Center's north tower.

Two F-15 fighter jets from Otis Air National

Guard Base on Cape Cod, 153 miles from New

York City, are ordered to go to New York.

8:52 F-15s become airborne.

8:55 Flight 77 stops flying west and turns east.

8:56 Air traffic controllers in Indianapolis lose radar contact with Flight 77.

9:02 United Flight 175 hits the World Trade Center's south tower.

9:03 Boston Air Route Traffic Control Center halts traffic from its airports to all New York area airspace.

9:05 Flight 77 appears as an unidentified blip

on radar over West Virginia.

9:06 Order is expanded to include the entire Northeast from Washington to Cleveland. FAA's air traffic control center outside

Washington notifies all air traffic facilities nationwide of the suspected hijacking of Flight 11.

9:08 FAA orders all aircraft to leave New York area airspace and orders all New York-bound planes nationwide to stay on the ground.

9:17 New York City airports shut down.

9:24 FAA notifies NEADS about Flight 77.

9:24 Two F-16 fighter jets from Langley Air Force Base in Hampton, Va., ordered to take off for Washington.

9:26 FAA halts takeoffs nationwide. Airborne international flights told to land in Canada.

9:30 Two F-16s take off from Langley AFB.

9:37 Flight 77 hits the Pentagon.

9:45 FAA orders all planes in the air to land at the nearest airport.

9:48 Capitol and West Wing of White House evacuated.

10:03 United Flight 93 crashes 80 miles southeast of Pittsburgh.

10:15 2,000 planes have landed in the U.S. since 9:45 order was issued.

12:16 All aircraft ordered to land at 9:45 have landed.

SOURCE: Compiled from wire sources, press reports and government records