LOUISVILLE, Colo. (AP) — Search teams looked for two missing people on Sunday in the snow-covered but still smoldering debris from a massive Colorado wildfire, while people who barely escaped the flames sorted through what was left after the blaze and investigators tried to determine its cause.

The flames ripped through at least 9.4 square miles and left nearly 1,000 homes and other buildings destroyed in suburbs between Denver and Boulder. It came unusually late in the year following an extremely dry fall and amid a winter nearly devoid of snow. Experts say those conditions, along with high winds, helped the fire spread.

Rex and Barbara Hickman sifted through the ashes of their Louisville home with their son and his wife.

Their son Austin cut a safe open with a grinding tool to reveal gold and silver coins, melted credit cards, keys and the charred remains of the couple’s passports.

They evacuated with their dog, their iPads and the clothes on their back. Rex Hickman said he was heartbroken to see there was nothing left of their home of 23 years.

“There’s a numbness that hits you first. You know, kind of like you go into crisis mode. You think about what you can do, what you can’t do,” he said. “The real pain is going to sink in over time.”

The couple have to find a rental property and clothes in the short-term, and their insurance company told them Sunday it would take at least two years to rebuild their home.

“We know how fortunate we are,” Rex Hickman said. “We have each other. We have great friends, wonderful family. So many people have got to be suffering much more than we are, and we feel for them.”

While homes that burned to the foundations were still smoldering in some places, the blaze was no longer considered an immediate threat — especially with Saturday’s snow and frigid temperatures.

Authorities initially said everyone was accounted for after the fire. But Boulder County spokesperson Jennifer Churchill said the reports of three people missing were later discovered amid the scramble to manage the emergency. One was found alive, officials said Sunday.

Crews were still looking for a woman at a home in Superior and a man living near Marshall. Boulder County Sheriff Joe Pelle said their homes were “deep in hot debris and covered with snow. It is a difficult task.”

Other investigators were seeing if the missing people might have made it out, but not contacted their families or friends, Pelle said.

Ruthie Werner of Louisville told NewsNation Now that she was shopping at a Target and exited the store to an apocalyptic scene — thick smoke and people scrambling to get out of the parking lot.

“Everything’s been so dry. (The fire) came so quickly. … It took awhile to get out of there, which is hard when you’re managing really scared children.”

Werner said she managed to get home and the family immediately evacuated, without waiting for orders.

“The whole town … just knew it was time to go because of how heavy the smoke was. Thankfully, so many people did get out.” Werner said there was just enough time to gather up the family dog and dog food — and a bottle of wine, “because I’m … like, I’m gonna need this tonight.”

Werner said her home was spared, unlike that of so many neighbors: “I’m a designer … A lot of the homes I helped design … were lost.”

Colorado Gov. Jared Polis and federal emergency officials visited some of the damaged neighborhoods Sunday morning.

“I know this is a hard time in your life if you’ve lost everything or you don’t even know what you lost,” Polis said after the tour. “A few days ago you were celebrating Christmas at home and hanging your stockings and now home and hearth have been destroyed.”

The cause of the fire is still under investigation. Utility officials found no downed power lines around where the fire broke out.

Pelle said Saturday authorities were pursuing a number of tips and had executed a search warrant at “one particular location.” The sheriff refused to give details again Sunday, including whether he thought the fire was set.

“It’s complicated and it’s all covered with a foot of snow,” Pelle said of the scene where the fire started. “The outcome of that investigation is vital — there is so much at stake. We are going to be professional. We are going to be careful.”

Of at least 991 buildings destroyed by the fire, most were homes. But the blaze also burned through eight businesses at a shopping center in Louisville, including a nail salon and a Subway restaurant. In neighboring Superior, 12 businesses were damaged, including a Target, Chuck E. Cheese, Tesla dealership, a hotel and the town hall.

The two towns are about 20 miles northwest of Denver with a combined population of 34,000.

The flames stopped about 100 yards from Susan Hill’s property in Louisville. She slept Saturday night in her home using a space heater and hot water bottles to stay warm since her natural gas service had not been turned back on.

She choked up as she remembered seeing the sky change color and recalled nervously sprinting out of town with her college-age son and the dog, cat and a fire box with birth certificates and other documents.

“I don’t even know how to describe it,” she said. “It’s so sad. It’s so awful. It’s just devastating.”

Utility crews expected to restore electricity to the homes still standing Sunday, but warned gas service might take longer to get back.

People lined up to get donated space heaters, bottled water and blankets at Red Cross shelters. Xcel Energy urged other residents to use fireplaces and wood stoves to stay warm and keep their pipes at home from freezing.

Superior resident Jeff Markley arrived in his truck to pick up a heater. He said he felt lucky to be “just displaced” since his home is intact.

“We’re making do, staying with friends, and upbeat for the new year. Gotta be better than this last one,” Markley said.