Air Force One on Sept. 11, 2001, sat waiting on the tarmac for then-President George W. Bush after a visit to Emma E. Booker Elementary School in Sarasota, Florida, where he was talking to a classroom full of second-graders.
In the pilot's seat was Col. Mark W. Tillman, who spoke of 9/11 during a Friends of Scouting fundraiser luncheon Tuesday at the Chattanooga Convention Center.
Tillman had seen a television report that a "light aircraft" had hit one of the towers at the World Trade Center, he said. It's what everyone believed at first. Tillman told the crew to expect a presidential trip to New York because of the obvious loss of life there.
Then he got a phone call from the beige phone on board, used for classified communications.
"It's the relocation of the president of the United States," he told the luncheon crowd in Chattanooga. "The only time we're going to do this is when the country is under attack and we're going to war. It's all for the continuity of government."
(READ MORE: Chattanooga attorney recalls horror in World Trade Center Building 7 on 9/11)
Then Tillman got word a second plane had hit the other tower, and the shocking news was also relayed to Bush.
"At this point, significant events are starting to occur in the world," Tillman said. "[Chief of Staff] Andy Carr leans over and he talks to President Bush, and he lets him know that the country is under attack."
Air Force One was ready to move with the president aboard.
"We're ready to make things happen because we've accepted the president [on Air Force One]," Tillman said.
At that point, Bush was on the phone with Vice President Dick Cheney, who had "hunkered down" in a secret bunker. Cheney told Bush of preparations for him to also hunker down.
No dice.
"President Bush made the decision that he's not going to hunker down. Not a chance. A Texas man is not going to hide underground. He's going back into the fray," Tillman said. "Our plan of attack now is to get him back to Washington, D.C. - orders have changed."
By the numbers
Friends of Scouting Scout Executive Jared Pickens reported Tuesday the 17th annual Friends of Scouting luncheon and other efforts raised pledges, sponsorships and commitments of more than $370,000 in local support.
Bush was leaving the school when Tillman and company learned a plane crashed in Washington.
Time compressed and available information was confused and inaccurate. It had been less than an hour since the first plane struck.
(READ MORE: Chattanooga area leaders honor first responders, call for unity on 9/11 anniversary)
"As he starts toward us, the fog of war starts to happen," Tillman said. "We're told a truck bomb has blown up the Pentagon, numerous car bombs have gone off in the Capitol area."
For Tillman, it's unreasonable to return to Washington, now a war zone, but that's what Bush wants.
All four engines on Air Force One were ready as Bush stepped on board, and minutes later Tillman was flying the president over the Gulf of Mexico.
The plan still was to return to Washington.
Air Force One's 47 phone lines, because of the amount of phone traffic, were reduced to three, while the plane's loudspeakers carried the conversation between Bush and Cheney because everyone had to hear the discussion as everything was happening so quickly.
"The vice president lets him know that of all the hijacked aircraft, there's only one now that's still suspect and that's over the Ohio Valley," Tillman said. "It's Flight 93, United 93."
Cheney asked Bush for "shoot-down authority" for the aircraft, he said.
Permission granted.
The next thing they heard was Flight 93 was down.
"We assumed we've shot down our own people," Tillman said.
There were no signs of life. They would learn later a group of passengers stormed the cockpit before it could reach the capital.
They headed for an Air Force base in Louisiana as Air Force One was named the next target and fighter and radar planes were needed for escort, he said.
"Within minutes Houston Center comes alive on our frequency," he said. "Air Force One, Air Force One you have fast-movers at your 7-o'clock."
Unidentified fighter planes were supersonic, headed toward the president's plane and fighter escorts hadn't been requested yet.
Who are they?
"Air Force One, Air Force One," Tillman recounted, using his best Texas accent to imitate the fighter pilot. "We're flying two F-16s, we're your cover."
Tillman called it "the best radio call ever."
Barksdale Air Force Base in Louisiana was the next stop, but Bush was determined to get back.
"'Tillman. Time to get home. Now,'" Bush told him.
"Everybody's in the plane and we are hauling across America doing about .92 Mach," Tillman said.
"As we descended into Washington, D.C., we overflew the Pentagon and you can actually see damage. The Pentagon is smoldering," he said.
But even as smoke still rose from the ruins at the Twin Towers, the Pentagon and Shanksville, Pennsylvania, Air Force One returned safely to the nation's capital. The president was able to address a shattered nation that evening that would never be the same.
(READ MORE: Sen. Blackburn introduces bill to commemorate 9/11 by making it a federal holiday)
The country, in hindsight, might have done better, Tillman said.
But a positive, if one can be found, was that the country unified in the face of tragedy.
"America came together on Sept. 11," Tillman said. "Everywhere we went, America stood strong. Sons, daughters, youngsters were out there chanting, 'U.S.A., U.S.A.'"
"If I could change anything right now, it would be to make everybody understand that it doesn't matter what color or what ethnicity you are, it's time to get back together again," he said.
Contact Ben Benton at bbenton@timesfreepress.com or 423-757-6569. Follow him on Twitter @BenBenton.