JEFFERSON COUNTY — An early-spring fire that burned through 4,500 acres and 23 homes and killed an elderly couple continued to rage almost at will across parched foothills late Tuesday, prompting officials to alert thousands more residents to prepare to join neighbors already forced to evacuate their homes.

Officials have identified the two victims of the Lower North Fork fire as Sam Lamar Lucas, 77, and his wife, Linda M. Lucas, 76. Authorities were also searching late Tuesday for a woman who is unaccounted for in the fire area.

Sam Lucas was found outside, and his wife inside, a home deep within the burned area. Fire officials said they didn’t know whether the couple had tried to escape. Their deaths remain under investigation.

Despite the efforts of about 200 firefighters and the benefit of lighter winds, authorities failed to gain much, if any, control over the fast-moving fire Tuesday, said Jacki Kelley, a Jefferson County Sheriff’s Office spokeswoman. Today, the firefighting team will grow to 400, with crews coming in from across the West.

“We’re finally getting the resources we needed yesterday,” Kelley said. “We’re going to be fighting this fire 24 hours a day until we get containment.”

Whipped by strong winds and fueled by unusually dry conditions, the fire roared across thousands of foothill acres southwest of Denver south and east of U.S. 285 starting Monday.

Jefferson County officials said they believe the fire began as a controlled burn set a week ago by the Colorado State Forest Service on land belonging to the Denver Water Board, and that it sprang back to life Monday. However, Joe Duda, deputy state forester, told Channel 4 News that the service is in no way taking responsibility for having anything to do with the current fire.

“I think it’s fairly unusual for this to happen so long after the fact, and so we’ll wait for the sheriff’s report,” he told the television station.

Tuesday afternoon, authorities alerted residents of an additional 6,500 homes that they should prepare to evacuate, after a spot fire flared 1 mile northwest of Waterton Canyon. About 2,500 homes had already been evacuated by that time.

The most recent areas under pre-evacuation notice include: Dear Creek Mesa, Deer Creek Canyon Park, Homewood Park, Hilldale Pines, South Murphy Gulch Road, Watson Gulch Road, an area southeast of South Turkey Creek Road, White Deer Valley and Jennings Road.

Tuesday afternoon, Jefferson County officials led reporters deep into the backcountry to scenes of Monday’s devastation.

Tree stumps and the charred foundations of what were once homes still smoldered, marked by blackened concrete and molten metal. Flames still shot out of a gas line in one of the destroyed homes. The house numbers on a post near the driveway were melted into the wood.

Dan Hatlestad, public-information officer for the Jefferson County Incident Management Team, said it took only minutes for the fire, with temperatures above 1,000 degrees, to flatten the homes.

Twenty residents had to be pulled out of the area at the last minute by fire crews and emergency vehicles. The smoke was so thick that firefighters had to stick their heads out the windows as they drove in order to see the roadway.

One family became so disoriented that their two vehicles drove off the road, and fire crews had to save them and their pets, Hatlestad said.

David and Jill Owens, whose home was in the heart of the burn area, watched Monday as the smoke plume grew just miles from their driveway. The Owenses, their two young children, three dogs and two cats last saw their home at 5 p.m. Monday.

“It was clear we needed to go,” David Owens said.

When they awoke Tuesday, they saw their home on a local TV newscast. It was, David Owens said, ashes. The only recognizable parts were boulders and concrete from the back patio.

About 25 evacuees spent Monday night at a shelter set up at Conifer High School. Some chose to spend the night in their vehicles in the school’s parking lot to be with their pets.

Julie and Tim White spent an anxious night with their five dogs and three cats. The couple just finished building their home last May and were forced out Monday evening. Animal-rescue workers got into their home and brought their pets to them as they watched smoke billow from afar.

“We’re waking up to the fact that we might lose our house,” Tim White said Tuesday. “We’re not really sure what we’ll do next.”

By Tuesday afternoon, amid fear that the ranks of evacuees had outgrown Conifer High, the evacuation center was moved to West Jefferson Middle School.

The Lower North Fork blaze may be the first in decades to claim the lives of nonfirefighters. Steve Segin, spokesman for the U.S. Forest Service, said that since he began working in 1999, he can’t recall a single civilian killed in a wildfire in Colorado, although numerous firefighters have lost their lives. A search of Denver Post records going back to 1982 found no civilian deaths.

“It’s pretty remarkable,” Segin said. “We’ve been fairly lucky.”

The terrain, dry conditions, abundant fuels for fire and winds on Monday were reminiscent of the 2002 Hayman fire, which burned 138,000 acres.

“It’s a combination of problems for us,” said Kelley, the Sheriff’s Office spokeswoman.

The Federal Emergency Management Agency has authorized the use of federal funds to help with firefighting costs for the Lower North Fork fire in Jefferson County, according to Jerry DeFelice, FEMA spokesman.

FEMA funding pays 75 percent of the state’s eligible firefighting costs. The money does not cover damage to homeowners or businesses and does not cover other infrastructure damage caused by the fire.

Staff writers Monte Whaley, Kieran Nicholson and Karen Augé contributed to this report.

“On to greener pastures”

At Conifer High School, Mark Sustek packed his lawn chair and cooler into the back of his overflowing Ford F-150 pickup Tuesday evening. “On to greener pastures,” he joked. “you can’t go home but you can’t stay here. I just hope I eventually have a home to go back to.”

Hayman survivor returns favor

Terry Neal, whose home is not in the fire zone, showed up at the The West Jefferson Middle School shelter to offer help. “During Hayman (fire), you would not believe the people who helped me and my family. I said then I’d always help anybody I can. I owe it. If you live up here you either owe it or you will, either your place has burned or it will someday.”

Near-zero visibility

Visibility in some areas around the fire was so bad Monday that some fleeing residents drove their vehicles off dirt roads and into ditches because they couldn’t see, said Claire Schmidt, who lives off North Tail Circle and spent Monday night in the shelter. “It’s like in some places one home is there, and the next is gone.”

Power’s out, and they’re out too

Cris Nowakoski and his wife put on headlamps and packed a few things from their Pleasant Park area home, after the power went out about 7 p.m. Monday. “It’s a blur,” he said. “I woke up this morning thinking it was a dream.”

Safe but on edge

Maggie Whalen and her husband, Pete, fled their home off Gold Spur around 7:30 p.m. Monday with their two dogs, Sirius Black, 12, and Molly, 13. Their two horses were rescued by emergency workers. “The winds have just been crazy. But we got what we needed out of there and that’s what matters.” Sirius Black was a nervous wreck after the evacuation so Whalen was scrambling Tuesday to fill a veterinarian’s prescription for Xanax. “Maybe I’ll take some too.”

Grabbing hold of important stuff

Christopher Prado was ordered to evacuate his Pleasant Park home about 8:15 p.m. He grabbed a guitar, some other musical instruments and a birth certificate. It took him about an hour to get ready to leave. He took comfort in knowing that there was still some snow on the ground around his home. “There’s a lot of things that could be lost today. But at the same time, you have to grab hold of the important stuff.”

“We all come together”

Lisa Paris has lived in the King Valley community long enough to have survived the Hayman fire, the Snaking Gulch fire and a few other less-legendary blazes. Back then, she didn’t know many people, so she paid $1,500 a week to board the family dogs. Tuesday, she put out an offer to babysit her neighbors’ kids or dogs, or even provide a couch or spare bed for anyone who needs one this week. “This is the kind of community where nobody ever makes a peep ’til you need it, then we all come together.”

Compiled by Joey Bunch, Monte Whaley, Karen Augé, Jordan Steffen