As the five-year anniversary of 9/11 approaches, major questions about the terrorist attacks remain unanswered. “Hardball” takes a look at the top mysteries surrounding the deadliest terror attack on American soil starting with the activities al-Qaida ring leader Mohammed Atta on the evening of Sept. 10, 2001.
It was Atta who took control of the first hijacked aircraft, American Airlines Flight 11, and told passengers, "Nobody move, everything will be OK. If you try to make any moves, you'll endanger yourself and the airplane."
Twenty-three minutes later, Atta flew that plane into the North Tower of the World Trade Center. The night before, Atta went to Portland, Maine, a trip that has mystified terrorism experts for five years.
"There's a real question there because he took a tremendous risk in going to Portland the night before and then having to catch a commuter flight to Boston,” said Roger Cressey, who was director of transnational threats for President Bush's National Security Council. “Given the vagaries of traveling on the East Coast, (it was a) tremendous risk to take. And so, we still don't know what he was doing there."
Atta grew up in Egypt and studied urban planning in Germany. He lived in Hamburg in the 1990's and is now believed to have trained at an Al-Qaida camp in Afghanistan in 1999. In the spring of 2000, Atta entered the United States and enrolled in an aviation school in Venice, Fla.
On Sept. 10, 2001, Atta picked up another 9/11 terrorist, Abdul-Azzia Al-Omari, at the Milner Hotel in Boston. They drove a rented Nissan to Portland, Maine, and arrived at the Comfort Inn Hotel at 5:43 p.m.
At the time, Tyler Drumhiller was a top official at the CIA, responsible for all European Operations.
"Might have just been doing surveillance detection just to see if somebody might have been following him up in that area,” Drumhiller said. “It's hard to tell."
Financial records and bank video show Atta and Al-Omari made two ATM withdrawals in Portland, and the men were reportedly spotted at an area Wal-Mart, as well as in the parking lot of a Pizza Hut restaurant.
On the morning of 9/11, Atta and Al-Omari drove to Portland International Jetport and boarded a 6 a.m. commuter flight to Boston's Logan International Airport.
"It is possible that he calculated that security would be less stringent in Portland, Maine, than it would be in Boston,” said terrorism expert Steve Emerson.
Another theory is that the 9/11 ringleader was concerned about a last-minute weather glitch or traffic jam in Boston.
"I suspect they were casing a fallback position to launch from if, for weather or security, they couldn't get out of Boston,” Drumhiller said. “Usually in these types of things you have your initial plan and you have a fallback plan. And that may have been what he was doing."
The other possibility is that Atta went to Portland for a final meeting with an unknown supporter. Drumhiller said it could have been "to make the final arrangements, to sort of close out everything they were doing to wrap up their time in the states."
Once Atta's commuter flight landed in Boston, phone records show he took a call from another 9/11 hijacker, Marwan Al-Shehi. Investigators believe the call was to confirm the attacks were ready to begin.
On American Airlines Flight 11, Atta joined four other hijackers. That aircraft hit the North Tower at 8:46 a.m. United Flight 175, also from Boston, hit the South Tower at 9:03 a.m.
"One of the things we did at the White House was push the FBI to focus on Portland to determine whether or not there were people there that they might have met with,” Cressey said. “We went through the logs of ferries leaving Maine, and we went through the logs of airlines and anything associated with potential for a terrorist cell to support Atta. And we came up empty."
So, did Mohammed Atta go to Portland because of security issues? Did he meet with somebody in Portland who helped him with the attack? That raises a larger issue, and that is: At any point did anybody in the U.S. knowingly help any of the 19 terrorists prepare for the attack? We will examine that 9/11 mystery in our next report.