Many firefighters died at the World Trade Center because they ignored orders to evacuate, not because of lapses in training or communication, former mayor Rudolph Giuliani contends.

"They weren't going to abandon ship," Giuliani said in an interview to promote his new book, Leadership.

Giuliani also said he expected to re-enter politics, saying another run for mayor was out but campaigns for president, U.S. senator or New York governor were possible.

"I've learned that you don't cut off options, and I have no idea of what the future will bring," Giuliani said. "I think I'll want to go back to government again. Maybe it will be appointed office."

Giuliani is mentioned frequently as a candidate to head the new Department of Homeland Security being set up by President Bush in response to the Sept. 11 attacks.

In the book, due in stores Tuesday, Giuliani wrote that he asked Bush three days after the terrorist attacks if he could personally execute Usama bin Laden if U.S. forces captured him.

"I am sure he thought I was just speaking rhetorically," Giuliani wrote. "But I was serious. Bin Laden had attacked my city, and as its mayor I had the strong feeling that I was the most appropriate person to do it."

The former mayor also said "there's a good chance, a really good chance" that he and girlfriend Judith Nathan would announce wedding plans soon.

In the interview Friday, Giuliani questioned two reports by management consulting firm McKinsey & Co. that concluded poor organization, faulty radio equipment and a lack of training hurt the rescue effort.

"They don't know most of the things that happened," Giuliani said of the consultants, who were hired by the Bloomberg administration to analyze the responses of the fire and police departments.

A McKinsey spokesman could not immediately be reached to comment Sunday and a Bloomberg administration spokesman declined comment.