New York officials wouldn't have done much differently in the days leading up to the Sept. 11, 2001, attacks, even if they had known about an August presidential briefing paper warning of terrorists casing city buildings, Rudolph Giuliani said Wednesday.

Testifying before The National Commission on Terrorist Attacks Upon the United States, which held hearings this week in Manhattan, the former New York City mayor said most intelligence information provided by federal officials had always pointed to the city's bridges and tunnels as possible terror targets.

"I do think the interpretation would have been more in the direction of suicide bombings than aerial attacks," Giuliani said one day after his top emergency management commissioners were grilled over their Sept. 11 response.

Raw Data: 9/11 Panel Statement on Crisis Management Flaws

The Aug. 6, 2001, intelligence briefing for President Bush — titled "Bin Laden Determined To Strike in U.S." — referred to evidence of buildings in New York being looked by terrorists as possible targets. It mentioned New York or the World Trade Center three times.

"If that information had been given to us, or more warnings had been given in the summer of 2001, I can't honestly tell you we'd do anything differently," Giuliani testified.

"We were doing at the time everything we could think of ... to protect the city."

The Aug. 6 presidential daily briefing (PDB) has been the center of much criticism of the Bush administration as Democrats and others argue the White House should have taken the threat more seriously. The president, his national security adviser, Condoleezza Rice and other administration officials maintain there was no clear information in that PDB pointing to a specific threat.

Giuliani's testimony was interrupted with angry outbursts by victims' families, including chants of "One-sided!" and "Put us on the panel!" One man, a longtime Giuliani adversary, was tossed out of the hearing after shouting at the panel to "ask some real questions!"

The heckling was a sharp contrast to some of the questioning from commission members, who gave Giuliani a warm welcome and praised his leadership following Sept. 11.

It was about 90 minutes into his testimony that Giuliani was shouted down by family members of the trade center victims.

"My son was murdered because of your incompetence!" shouted Sally Regenhard, whose firefighter son died in the trade center. Seated three rows behind Giuliani, she jabbed her finger at the former mayor and waved a sign that read "Fiction" as he gave the city's emergency response a glowing review.

"You're simply wasting time at this point," commission head Thomas Kean told the family members.

"YOU'RE wasting time!" came the angry reply.

Giuliani finished his testimony and abruptly left the auditorium minutes later, leaving many family members upset that they received few answers. Monica Gabrielle, who lost her husband, Richard, called it a "lost opportunity."

"This was not a time for Rudy Giuliani to talk about all the great things he did on 9/11," she said. "He can save that for his talking tours. He should have told us what went wrong and what we should do now."

The acrimonious hearing brought together the mayor, who became a symbol of heroism for his steady response to the attack, and the activist relatives who have become a voice of dissent over his administration's emergency planning and response.

Their complaints have been supported by a growing mass of critical findings on gaps in command, control and communications among New York's agencies in charge of emergency response.

The anger directed at Giuliani came on the second and final day of hearings in New York by the Sept. 11 commission, created by Congress last year to investigate the attacks and advise the country on ways to avoid future attacks. The hearings resume in Washington on June 8-9 and the final report is due July 26.

Just as Giuliani finished testifying, Christopher Brodeur — a New Yorker who became one of Giuliani's most ardent critics during his two terms in City Hall — jumped out of his seat.

"Three thousand people are dead!" Brodeur yelled before security guards escorted him out. "They were not killed because he's a great leader. ... Let's ask some real questions!" A second spectator was also ejected.

The former mayor and his commissioners were widely hailed for their efforts after two hijacked planes slammed into the twin towers, killing 2,749 people and rattling the city's psyche.

But on Tuesday, commission member John Lehman said the failure of city agencies to communicate effectively on 9/11 was a scandal "not worthy of the Boy Scouts, let alone this great city."

'Our Enemy Is Not Each Other'

Giuliani said in his opening statement that the commission's priority should be preventing a new attack, not assigning blame.

"Our enemy is not each other, but the terrorists who attacked us," Giuliani said. The mayor acknowledged there were "terrible mistakes" made on Sept. 11, but attributed that to the unprecedented circumstances.

After testifying, Giuliani suggested that Lehman owed his staff an apology.

"I was upset about that comment and the Boy Scout thing," Giuliani said outside the hearing. "They did the best job that anybody could."

Commission member James Thompson, before questioning Giuliani, said the panel was "not engaged in a search for blame, not engaged in a search for villains." Instead, he said, the commission hoped to save the lives of other Americans - a comment that drew more applause.

Giuliani pointed out that the bravery and quick thinking of city rescuers under brutal conditions had saved thousands of lives.

"Maybe 8,000 more, maybe 9,000 more than anyone could rightfully expect" were brought to safety before the towers collapsed, Giuliani said. About 25,000 people were evacuated from the World Trade Center.

He began by describing his actions and feelings on Sept. 11, recounting a morning that began at breakfast with two friends and quickly turned into unimaginable horror. He recalled his final meetings with several victims, and he described the scene when the first tower collapsed.

"It first felt like than earthquake, and then it looked like a nuclear cloud," Giuliani said. As Giuliani remembered watching a man leap from around the 102nd floor, family members began to cry, clearly disturbed by the account.

Just before Giuliani took the stand, the commission released a 10-page staff report saying that basic flaws in the city's emergency 911 phone system denied people inside the World Trade Center potentially lifesaving information.

The 911 phone system's operators and dispatchers were unaware that fire chiefs were evacuating the doomed twin towers because the city had no way of relaying that information, the commission staff concluded.

With the buildings' public address systems out of service, workers inside the buildings called 911 for help but were not told to evacuate, according to the report, which was the second part of the most comprehensive probe to date of New York's response to the attacks.

An unknown number of victims in the south tower might have had a better chance of survival if 911 operators had instructed them not to flee upward, where some found locked roof doors and no hope of escape, the report concluded.

"In several ways, the system was not ready to cope with a major disaster," the report said.

Current Mayor Michael Bloomberg also testified, complaining that New York was recently advised by Congress that its homeland security funding for the 2004 budget year would be cut by nearly 50 percent.

"This is pork barrel politics at its worst," the mayor said. "It also, unfortunately, has the effect of aiding and abetting those who hate us and plot against us."

The Associated Press contributed to this report.