NORTH CHARLESTON, South Carolina (AP) -- Nine caskets lined the front of a coliseum as thousands of firefighters from across the nation, their hats in their hands as bagpipes played, honored nine colleagues who died battling a furniture store blaze.

Uniformed escorts walked the men's wives, siblings and children to their seats in a long procession of red carnations, tears and hugs.

Monday night's fire created the single largest loss of firefighters' lives since the September 11 terror attacks.

The faces of its victims looked out from large photos set beside each casket: Capt. William "Billy" Hutchinson, 48; Capt. Mike Benke, 49; Capt. Louis Mulkey, 34; Mark Kelsey, 40; Bradford "Brad" Baity, 37; Michael French, 27; James "Earl" Drayton, 56; Brandon Thompson, 27; and Melvin Champaign, 46. (Watch why the fire department's chaplain says, "We're kind of numb, but we'll come through it" )

A procession of fire trucks wound through the streets in their honor Friday, and outside the North Charleston Coliseum, more than 250 firefighters formed a human passageway for the men's family members, each wearing a red carnation, to enter the service with uniformed escorts.

"When we lose one, it affects us all," said Lt. James Diego, who drove from the Newport News, Virginia, Fire Department with several colleagues. "Most of us have suffered some sort of loss in our careers, and it's a way to pay back the people who supported us when we had a line of duty death."

Black bunting hung over the lighted signs around the 9,000-seat arena, and officials planned to broadcast the service to screens outside and inside an adjacent performing arts center and nearby convention center.

Nearby, a retired Marine stood with an American flag.

"I joined the Marine Corps when a couple of these kids were just being born. If that don't make you cry, you're not a human being," said Robert Turner, 47. "These guys do the same thing that we did in the Marine Corps. It's all duty. It's all honor. It's all for your country or for somebody else. You don't join the service to get rich. You don't become a firefighter to get rich."

Among those expected for the service were former New York Mayor Rudy Giuliani and former Arkansas Gov. Mike Huckabee -- both presidential candidates -- as well as Barbara Richardson, wife of Democratic New Mexico Gov. Bill Richardson, who is also running.

But South Carolina Firefighters Association President Joe Palmer said dignitaries would be seated at the back, well away from firefighters' families.

"This event is about the firemen who were lost -- honoring them and their families. It is not a political event and shouldn't be politicized in any way," said Jeff Zack, a spokesman for the International Association of Firefighters. He said firefighters were coming from as far as Arizona and Alberta, Canada.

The investigation into the warehouse fire was still under way Friday.

Officials on Thursday released tapes of several 911 calls about the fire. While federal investigators have not confirmed where the blaze, some of the 10 recordings bolster the assertion several city fire officials have made that it likely started at the back of the store in a covered space between the showroom and a warehouse crammed with furniture.

A store employee told The Associated Press that workers frequently smoked cigarettes in that area and were strongly cautioned to carefully throw them away.

Federal investigators have not discussed possible causes for the fire, and have not revealed if they are considering whether a cigarette could have started the blaze.

"We have made fantastic progress in this investigation, however, it still has to be a very systematic, deliberate investigation," said Earl Woodham, a spokesman for the federal Bureau of Alcohol, Tobacco, Firearms and Explosives.

In a gesture of solidarity, medics from the Framingham, Massachusetts, Fire Department hung their department T-shirt at a makeshift memorial outside the charred store.

Before the service, a long procession of about 100 fire trucks wound through streets lined with mourners, passing firehouses and the gutted furniture store on its way to the memorial service. The first of the nine funerals was planned for later Friday.