NEW YORK - Relatives of World Trade Center victims upset by plans to move this year's Sept. 11 commemoration away from ground zero have reached a deal with the city that will allow them to mourn at the site where their loved ones perished.

Mayor Michael Bloomberg met with the families Thursday and agreed to their proposal that they be allowed to descend briefly into the seven-story pit that was the trade center's basement to pay their respects.

The city had announced last month that the sixth anniversary ceremony could not be held at the 16-acre trade center site, as it had been each year since the 2001 attacks, because the construction going on there made the area too dangerous for such a large gathering.

But Bloomberg said Thursday that the families' proposal for “a very limited and controlled level of access” to the pit had been deemed safe by the Port Authority of New York and New Jersey, which owns the lower Manhattan site.

“We will work with the Port Authority to allow family members to safely descend the ramp in a single file stream that keeps moving into a limited area below grade to pay respects and to then ascend back to street level,” he said in a statement.

Family members arrived at the meeting armed with charts and a map outlining their proposal, said Sally Regenhard, whose firefighter son was killed in the Sept. 11 attack. Ultimately, the mayor agreed to allow family members to descend all the way to the level of bedrock.

“They'll just have a moment to toss their flowers on the sacred ground,” said Regenhard, who declared herself “very, very happy” with the agreement.

Like so many victims' relatives, Regenhard has not received any of her son's remains and has had nothing to bury. For those families especially, still awaiting DNA tests of newly found fragments, the attack site is hallowed ground, she said.

“I feel my son is there,” Regenhard said Thursday night. “He could be there in a physical way but also in a spiritual way.”