The chairman of the military Joint Chiefs of Staff (search) and the prosecutor handling charges against suspected Sept. 11 terrorists in Germany will testify next week in the final hearing of the commission investigating the attacks.

The hearing next Wednesday and Thursday will track the development of the plot from its origins in the 1990s. On the second day, the 10-member panel will review the national emergency response by the Federal Aviation Administration (search) and U.S. air defenses on the day of the attacks.

Among the questions the panel wants answered: What was the federal government's protocol for responding to the Sept. 11 attacks? How well did the government perform that day? Are federal officials now ready in the event of future attacks?

"We will attempt to close the circle," said Thomas Kean, the commission's Republican chairman. "We will look back to the roots and growth of Al Qaeda (search), its previous attacks on the United States, its financing and international support, and how it plotted such detailed and intricate attacks on our soil."

"The commission will then turn again to the day of Sept. 11, 2001, to examine how the federal government learned of and responded to the attacks," he said in a statement.

Scheduled to testify in addition to Gen. Richard Myers, chairman of the Joint Chiefs, are top law enforcement and intelligence experts on Al Qaeda, including Matthias Krauss, who is handling the prosecution of the Al Qaeda cell in Hamburg, Germany, that was key to the hijacking plot.

Patrick J. Fitzgerald, a former attorney in New York who prosecuted alleged terrorists in the 1993 bombing of the World Trade Center (search) and the 1998 bombings of two U.S. embassies in Africa, also will testify.

Speaking on the emergency response will be Myers and officials from the FAA and the North American Aerospace Defense Command (search), or NORAD.

Relatives of Sept. 11 victims have said they want to know whether military jets could have been scrambled sooner after the first hijacked plane hit the World Trade Center at 8:46 a.m. on that fateful day. They believe quicker notification could have prevented American Airlines Flight 77 from crashing into the Pentagon more than 50 minutes later, killing 184 people.

The commission, which faces a July 26 deadline to issue its final report, is winding down its 1 year investigation after interviewing more than 1,000 witnesses, including President Bush, and reviewing more than 2 million documents.

Drafts of the Sept. 11 panel's final report point to several communication gaps and missteps by FBI and intelligence officials in detecting the plot and responding to the attacks and propose widespread reform, according to several commissioners.