The massive Las Conchas Fire had slowed on its path Tuesday, and firefighters were digging in as they kept the main blaze from advancing to Los Alamos National Laboratory and the Los Alamos community for a third day.

The fire had burned more than 61,000 acres by Tuesday but was expected to settle down overnight, according to fire officials. It was still zero percent contained, but fire crews made good progress building containment lines and burning out forest debris and brush.

Emergency assistance and expertise was arriving from throughout the U.S. on Tuesday, as containing Las Conchas was listed as a priority due to its proximity to LANL.

The fire began Sunday on private land near mile marker 35 on N.M. 4 — and quickly exploded, growing from 100 acres to 43,000 acres in just 18 hours. The cause is still undetermined, but officials think it was possibly sparked by a downed power line.

The fire could grow to be New Mexico's largest ever, surpassing the 94,580-acre Dry Lakes Fire of 2003 that burned in the Gila National Forest. "This fire has the potential to grow to 100,000 acres," said Los Alamos County Fire Chief Doug Tucker.

An estimated 9,000 people had evacuated Los Alamos by Tuesday afternoon. A few dozen had remained in the western neighborhoods of the town. Some of them were still packing and planned to leave. Others planned to stay as long as possible.

More than 350 firefighters were on the scene Tuesday, using heavy equipment on the ground, and tankers dropped fire retardant from the air.

Fighting fire with fire

Las Conchas ringed Camp May and sprinted toward Santa Clara Canyon late Monday and into Tuesday, according to Tucker. Portions of that area had already burned in the Cerro Grande Fire of 2000 and an older wildfire.

Tucker said Las Conchas had burned about 10,000 acres of the Cerro Grande Fire area, wiping out a nice stand of young aspen that was a sign of the area's recovery.

On Tuesday, the fire was continuing to burn west of Los Alamos, into the Valles Caldera National Preserve and south through Bandelier National Monument. A mile-wide tongue of it crept north within a mile of Santa Clara Pueblo land, according to Carl Schwope, operations section chief for the Southwest Area Incident Management Team.

Firefighters have fought for two nights in a row to prevent the Las Conchas Fire from swallowing Pajarito Mountain Ski Area. None of the structures have burned.

Schwope said a bulldozer was going to blade along Quemazon Trail. "That will push the fire to the west, away from Los Alamos."

He said areas along N.M. 4 and N.M. 501, both bordering lab property, looked good.

In the Valles Caldera National Preserve, the fire was burning through Cerro Medio. To keep it from pushing hard through the other hills, air support will ignite Cerros del Abrigo and possibly Cerros de los Posos. Like a burnout, the idea is using fire to fight fire. "We'll burn trees in the cerros from the top down," Schwope said, so when the fire reaches the hills, it can't climb up in the treetops and crown.

"When this (Las Conchas) fire lines up, it will crown. It will rip through there."

Taming a fire

While the fire isn't near the size of the Wallow conflagration in Arizona, it is squirrely and threatening a national resource, so a second Type I Southwest Regional Management Team arrived Tuesday evening to help. The teams have expert fire managers and natural disaster coordinators from various states. They'll divide the fire, each team focusing on corralling a different section of Las Conchas.

Taming the fire means putting a containment line around it and making sure nothing inside can send out a burning ember to spark a new fire, said Brad Pitassi, public information officer with the Type I Southwest Incident Management Team.

Hot Shot crews cut and clear a 3-foot line along one section of the fire's perimeter at a time. "A 3-foot line can stop a Wallow-size fire if it's on the ground, as long as it is not in the (tree) crowns."

Sometimes crews will build a contingency line miles away from the fire, just to make sure.

In some areas, crews will do small prescribed burns or burnouts 300 feet back toward where the fire is active.

A plane equipped with an infrared camera flies over the burned areas every night, looking for places where no heat comes off and remapping the fire's perimeter.

Only once an area is "cold" will fire managers deem it contained.

Even then, a firefighter will drive past the contained areas a couple of times a day to make sure no hot spots are missed.

"We're worst-case scenario thinkers," Pitassi said.

Good cooks

Frank and Pam Good at Bob's Bodacious BBQ on Diamond Drive were still cooking away on Tuesday. Their packed truck was parked out back. Their two dogs, "spice girls" Cinnamon and Pepper, were hanging out to greet the hungry National Guardsmen, police and fire managers that dropped by to eat.

Frank Good was prepping 200 pounds of pork and beef brisket to drive over to the emergency operations center. "You should take a few gallons of the (barbecue) sauce," his wife said.

The Goods bought the restaurant and its famous (very secret ingredient) sauce from original owner Bob Carlson in January. "Frank loves to cook," Pam Good said. "We bought the restaurant because the food was good and had a good reputation."

They weren't expecting a record-breaking cold winter, gale-force spring winds and now the fire. A lot of their customers experienced Cerro Grande. Pam Good said maybe if they had experienced it, they would be leaving already. Instead, they'll stay until they run out of food "or I see flames on the hill."

A constant voice

A couple of doors down from Bodacious BBQ is the KRSN AM1490 radio station. David Sutton, a Los Alamos native, and his wife, Gillian Sutton, bought it six years ago.

They aren't planning to evacuate "unless our house and the radio station burn down," David Sutton said, shrugging. "Then we'll go somewhere else."

They'll keep interviewing town officials and fire managers, stream it live on their Facebook page and keep their listeners informed of what's happening from within the town. "My Facebook page has just gone bonkers," Sutton said. "I didn't even know how to Facebook five weeks ago."

He's had listeners from all over the country, and places such as Australia and Denmark post comments and thank him for continuing to broadcast. "I never imagined the radio station would be so far-reaching," he said.

A town shut down

Los Alamos National Laboratory will remained closed until at least Thursday, with only essential personnel still allowed on-site.

Lab employees who get their paychecks automatically deposited will receive them as usual. Those who preferred manually cut checks can pick them up at Pojoaque High School from 7 a.m. to 7 p.m. Thursday.

Los Alamos residents can pick up their mail every weekday at the Pojoaque High School gym from 9 a.m. to 3 p.m. and from 9 a.m. to noon Saturday.

Contact Staci Matlock at 986-3055 or smatlock@sfnewmexican.com.