The Sept. 11 commission's (search) next public hearing, in New York, will focus in part on what's been done to improve poor communication and deal with a rivalry between the city's fire and police departments that hindered rescue efforts.

One study done for the New York Fire Department (search) shortly after the 2001 attacks attributed about 120 deaths in the World Trade Center to a lack of radio communication after a police helicopter sent a warning that the north tower looked ready to fall. Firefighters did not receive it.

The Sept. 11 attacks killed almost 3,000 people, including 343 firefighters and 23 police officers.

"The New York City hearings will be some of the most important, gut-wrenching and heart-pounding hearings we will have with the 9/11 commission," Democratic commissioner Timothy Roemer said. "They will entail some of the heroic and brave actions of people who saved others on 9/11.

"But we will also look at the mistakes and some of the problems," said Roemer, a former Indiana representative. "We will look at the question of how did we do on 9/11, and are we ready for the next attack or emergency?"

Former New York Mayor Rudy Giuliani (search) and Homeland Security Secretary Tom Ridge (search), and officials from the Port Authority of New York and New Jersey and from Arlington, Va., are among those scheduled to testify next Tuesday and Wednesday.

The first day of the hearings will focus on the emergency response, with video footage tracing the sequence of events. Giuliani will recount his experience on the second day of the hearings. He is expected to address what U.S. intelligence was shared with the city, particularly after President Bush reviewed an Aug. 6, 2001, intelligence briefing referring to evidence of buildings in New York possibly being cased by terrorists.

The Port Authority had oversight of the twin towers while first responders in Arlington were summoned when one of the hijacked planes crashed into the Pentagon. Their lessons are seen as critical for other cities that are planning their emergency response efforts.

At the hearing, the commission intends to review New York's response from the moment American Airlines Flight 11 crashed into the north tower at 8:57 a.m. until the building's collapse at 10:28 a.m.

Although the south tower was struck after the first, it fell 23 minutes earlier. After the collapse, a police helicopter sent a radio message warning the north tower might soon fall. Several police officers were able to escape, but firefighters' radios were not linked to the police transmission so they didn't receive the message.

The panel also will examine why Port Authority officials locked the rooftop doors of the Trade Center, preventing a potential helicopter rescue for those trapped on the top floors.

"This competition between the fire and police department created many problems. It was just a struggle," said Jerome Hauer, who headed New York's Office of Emergency Management (search) until 2000. He will testify at the hearings.

Hauer, now director of the Response to Emergencies and Disasters Institute (search) at George Washington University, explained that the police department did not like sharing its radios and frequencies, and fire officials were uncooperative as the two groups sought to be the primary response unit in emergencies.

"There has been a disjointed system and the city has actually gone backward," he said. "Instead of going to a command structure, the police department is now in charge and running public safety, and the fire department has been left behind."

Police, fire and the city's emergency management office, created in 1996 to coordinate the emergency response, have not yet agreed on who will take the lead in a terrorist strike or catastrophic accident. Hauer said that is troubling with upcoming major events such as the Republican National Convention.

Frank Gribbon, spokesman for the FDNY, said communication between the two departments has improved since Sept. 11, 2001, and firefighters now use more powerful radios capable of communicating with police. A police spokeswoman did not immediately return a phone call seeking comment.

Congress established the Sept. 11 commission to examine what led to the attacks and advise ways the government can do a better job of tracking terrorists and responding to an attack.

Last month, the panel heard from President Bush and Vice President Dick Cheney, former President Clinton and ex-Vice President Al Gore, as well as national security adviser Condoleezza Rice, CIA Director George Tenet and Attorney General John Ashcroft.

The 10-member bipartisan panel is to issue its final report on July 26.