While some sources inside the Pentagon who are believed to be credible have said a secret group identified hijackers a year before the Sept. 11 attacks, former members of the Sept. 11 commission (search) said on Wednesday they weren't buying it.

"Bluntly, it just didn't happen and that's the conclusion of all 10 of us," said Sept. 11 commissioner and former Sen. Slade Gorton (search), R-Wash.

The panelists appeared together Wednesday at a news conference to argue that the response to Hurricane Katrina (search) might have been more successful if more of the recommendations they had made last year had been implemented.

The commissioners, who now belong to the Sept. 11 Discourse Project to oversee the translation of their recommendations into reality, played down claims by the Defense Department's secret "Able Danger" group, whose members have said they identified terrorists in the United States more than a year before the 2001 attacks.

Earlier this month, the Pentagon confirmed that it had identified five people involved with Able Danger who claimed they had either seen a picture of lead hijacker Mohamed Atta (search) or had seen his name on a chart prepared in 1999 by the secret military intelligence unit. The Pentagon said that documents associated with the project had been destroyed.

Rep. Curt Weldon, R-Pa., accused the commission in August of ignoring intelligence about Atta while it investigated pre-attack intelligence and communication failures among U.S. law enforcement and spy agencies. According to Weldon, members of Able Danger identified Atta and three other hijackers as potential members of a terrorist cell in New York City. Weldon said Pentagon lawyers rejected the unit's recommendation that the information be turned over to the FBI in 2000 based on immigration rules at the time.

Two military officers also have publicly come to bat on the side of Able Danger. Army Lt. Col. Anthony Shaffer (search) and Navy Capt. Scott Phillpott (search) said the military group identified Atta before the attacks and met with staff members on the commission about their findings.

But the commission's chairman, Thomas Kean (search), said the panel had acquired no evidence anyone in the government knew about Atta before Sept. 11, 2001.

Weldon's spokesman, John Tomaszewski, said no commissioners met with anyone from Able Danger "yet they choose to speak with some form of certainty without firsthand knowledge."

The statements on Wednesday by the Sept. 11 commission come as Congress is set to take up the discussion on Able Danger with a hearing scheduled before the Senate Judiciary Committee later this month.

During the press event, the ex-commissioners also criticized the government for not putting in place changes recommended last year for homeland security and emergency response. They pointed most notably to the failure to improve communication systems, which they said might have saved lives after Hurricane Katrina.

"It is a scandal in our minds that four years after 9/11, we have not yet set aside radio spectrum to insure that police, firefighters and emergency medical technicians can communicate reliably during any kind of attack or any kind of major disaster," Kean said.

The commissioners also faulted state, local and federal authorities responding to Katrina for not having a clear chain of command, leading to some of the same confusion that plagued the Sept. 11 rescue effort.

"Many of these recommendations proposed by the 9/11 commission one year ago might have made a difference in saving lives and preventing loss of lives in this hurricane," said member Tim Roemer, a former Democratic congressman from Indiana.

Fox News' Catherine Herridge and The Associated Press contributed to this report.