By DIEGO IBARGUEN, Associated Pr ? With the peal of a Fire Department bell and the departure of an empty stretcher, the still-missing victims of the World Trade Center’s unspeakable horror were remembered Thursday in a ceremony without words marking the end of the 8 1/2-month cleanup.

The solemn service began with a bell sounding out the 5-5-5-5 fire code four sets of five rings, in memory of 343 fallen firefighters lost at ground zero.

The first bell rang at precisely 10:29 a.m., the time that the second tower collapsed in a screech of twisting steel and falling concrete on Sept. 11

The empty, flag-draped stretcher symbolizing the missing was brought up a 500-foot ramp from the pit where workers labored around the clock. An honor guard representing various agencies and victims’ groups placed it into a fire department ambulance.

After the stretcher was removed, a flatbed truck carrying the trade center’s last steel beam drove up the ramp. It had stood until Tuesday night, when it was cut down during a ceremony for ground zero workers.

The 30-foot column survived when the towers collapsed into a mountain of 1.8 million tons of rubble. For months it was covered by debris, but as the pile shrank the column was revealed, still standing where it was planted when the south tower was built. The beam was being taken to a hangar at Kennedy Airport for storage.

“This is the closest point I guess I can get to being with him again,” said David Bauer III, whose father a Cantor Fitzgerald worker was one of the more than 1,700 victims for whom no remains have been identified.

Hundreds of people began gathering at the site more than an hour before the service.

“It was tough to come here every day and now it’s tough to leave,” firefighter John Keating said.

Of the more than 2,800 people killed in the terrorist attack, remains of 1,102 have been identified. Nearly 20,000 body parts have been recovered.

City officials said the sifting for body parts in a landfill and the identification process will go on for months. Those human remains that cannot be identified will be retained, in case new technology someday makes it possible.

“It’s hard to remember on 9/11 with all of the twisted steel and concrete,” Mayor Michael Bloomberg said earlier on NBC’s “Today” show. “But the fact of the matter is the people that survived are the ones that we have to go on. We have to make sure they do not forget and that they build for the future.”

A small pile of debris which already has been combed through for human remains still needs to be removed, and workers were to resume that work Friday.

The unprecedented cleanup effort finished several months earlier than originally anticipated and at a fraction of the estimated cost. But while many victims have been identified, the end of the operation leaves numerous others without their family members’ remains.

Several family groups had asked Bloomberg to schedule Thursday’s service on a weekend, so that work and school schedules would not be disrupted. The mayor said the city avoided the weekend so it would not conflict with religious observances. He also said May 30 was the traditional date for Memorial Day.

To accommodate those who could not attend the ceremony, the family groups have planned their own service at ground zero on Sunday.

What to do with the site after the ceremony is under discussion. Control of the site will revert from the city to the Port Authority of New York and New Jersey, which owns the land.

Last week, the Port Authority and the Lower Manhattan Development Corp. announced the choice of architectural firm Beyer Blinder Belle as the urban planning consultant that will assist their staffs in producing a plan.

Beyer Blinder Belle will submit up to six proposals by July 1; a final plan is supposed to be chosen by Dec. 1.