The scar of a fast-moving fire divides the Hopper Lane Apartments, in the city of Santa Rosa. A few are still standing, low slung apartments, clustered by the half dozen, earth-toned and minimal, with through-the-wall air conditioners. Across a cul-de-sac, hot water heaters stand, lonely sentinels.

Nine of the 15 buildings here burned. Flames turned them into soft ash, white-pure in some places, grey, black and chalky in others.

As detectives from the Sonoma County’s Sheriff’s Office winnow down the missing persons list, the work of search and rescue teams is taking on a grimmer tone.

An all-volunteer search and rescue team from Alameda County is one of several set to this task. At the Hopper Lane Apartments, they’ve come with several dogs. Some are trained as trackers, to chase the scent of live people. Some have a second skill: nosing out human remains.

Sonoma County Sergeant Dave Thompson is overseeing this work.

“The scope I have never seen, and nobody here has ever seen this kind of a search effort or disaster zone,” he says.

Neither had Hopper Lane’s residents. Mormon missionary Sister Galene Carson watches the crews work. She and her husband arrived here from Orem, Utah less than a year ago. It was 2:30 a.m. when rescuers pounded on her door to make her leave.

“It was just red, and it was roaring and there was a whoooo sound. And it was -- we heard the pop pop pop -- I said to my husband go, go, go. We have to go, go, go.”

Her gaze falls on the orange-clad search team working behind the yellow crime scene tape. They carry buckets, and a screen box with a fine mesh.

Responders say cadaver remains tend to be cleared quickly. Ten days into this fire, says Thompson, really what this team seeks is evidence, in pieces and scraps.

“Maybe a vertebrae, maybe a three-inch piece of femur bone, and it looks exactly like the rest of the rubble in the house, unfortunately,” he says. “So it’s very, very slow searching. Hard to find, hard to pick up.”

An early boom of nearly 2,000 missing person reports has shrunk dramatically. Searchers now work where finding remains seems likely: because the missing person is elderly, or lacks mobility. Because phone calls and Facebook messages aren’t answered.

The work weighs on Thompson. He says in some ways, they hope to fail.

"We were at a site that was highly probable. We were digging, we were halfway done, and word came in that a neighbor had scooped this lady up on the way out. And when that news reached the search and rescue team who were on their knees in the dust and the rubble, a loud roar of happiness came up and we moved on to the next one."

Before this search concluded, that story had repeated at Hopper Lane: the missing woman had been found, alive.

Thompson and this search and rescue team have moved on to another site -- and hopefully another failure.