WASHINGTON (AP) — The grisly job of the teams digging through the Pentagon's charred wreckage only gets more awful as they move closer to the worst damage. But workers are pushing ahead by taking an almost numb, workmanlike view of the long and difficult task.

"If you're focused on your job and you're trying to do your job, it's almost a salvation," said Rudy Eversburg, a firefighter from Arlington County, Va. "No matter how horrific it may get, the thought of not doing the job never enters your mind. ... You're right there at ground zero, but that's what you've got to do."

Eversburg and fellow firefighter Peter DePuy were in the first trucks to respond Tuesday when a hijacked jetliner slammed into the Defense Department headquarters. It was pandemonium, they said Sunday while eating a quick lunch in a makeshift city set up in a nearby Pentagon parking lot to support the workers.

Now, the operation is more structured. There are many as 70 people inside the building at one time, including military personnel and FBI investigators combing debris for evidence, firefighters battling random blazes and reinforcing the structure, and search teams looking for victims. Workers have shored up much of the site and heavy equipment is beginning to clear rubble.

Over the weekend, recovery workers found, for the first time, a large number of bodies clustered together. They continued to pull remains from the wreckage early Monday morning as they dug deeper into the impact site.

Arlington County Battalion Chief Jim Bonzano announced that the first two search teams to arrive last Tuesday — from Montgomery County, Md., and Fairfax County, Va., — will leave later Monday. They could soon be deployed to New York or elsewhere. The teams will be replaced by a search and rescue team from New Mexico.

The recovery work — of bodies and evidence — is expected to take at least 10 days more days, Arlington County Fire Chief Ed Plaugher said.

Even though much of the wreckage has been stabilized, the conditions are hazardous, with waist-high piles of wet, shifting debris and, until Sunday, spot fires breaking out.

More of the Pentagon's roof also collapsed early Sunday morning, creating a landslide visible from the outside of the building but not stopping the operation. Benjamin Barksdale, battalion chief of the Arlington County fire department, said no one was hurt.

Eversburg and DePuy said they and their colleagues only really become aware of what they are seeing in bits and pieces — during shared meals or in a rare quiet moment.

"When you have a chance to sit down and think about it, it really hits you," Eversburg said.

Added DuPuy: "It's a lot of trying to block things out."

Grief counselors are on hand to talk about the devastating scenes the workers are encountering, but said they are delaying intensive de-briefings until after the work is done. "We are available if they want to unload it, but they have a mission," said Dodie Gill, a mental health expert with Arlington County. "We might have to take them off the job and that's what they don't want."

The Defense Department says 188 people — military and civilian employees at the Pentagon and the passengers and crew in the plane — were believed killed in the crash. On Sunday it said Cmdr. Dan Frederic Shanower, 40, of Naperville, Ill., was among the 124 people inside the Pentagon who were killed. His remains were only the second to be positively identified; the rest are listed as unaccounted for but presumed dead. In all, 88 sets of remains have been recovered and transported to Dover Air Force Base, Del., for identification and processing.

Pentagon and fire officials have said there is little chance of anyone coming out alive. But the recovery workers said they have to believe otherwise.

"You can't lose your hope," Eversburg said.

Members of a military mortuary unit, who retrieve remains spotted by recovery workers, said they take satisfaction in knowing they were bringing closure to victims' families.

Volunteers in the massive support compound, which offers everything from clean underwear to McDonald's hamburgers, are seeing the toll the task is taking.

"Some of them are having some real problems," said Ronald Hester of Asheboro, N.C., one of 37 Baptists handling much of the cooking and feeding chores. "Our people will just sit down and talk with them, and then they go back to work."