Hundreds still missing in Maui fires aftermath. The search for the dead is a grim mission.

Specialized teams of morticians, coroners and other death investigation experts are helping Hawaiian authorities with the grim task of identifying the people killed by last week's raging wildfire in Lahaina.

The known death toll as of Tuesday stood at 99, but authorities have said they expect more deaths will be reported as searchers sift through the toxic rubble. The intensity of the flames fueled by wood, carpet and other materials probably charred some bodies beyond recognition. Some people died in their cars, where burning rubber and gasoline may have fed flames as engine blocks melted.

"We need to help find those who have perished, and it's ongoing," Hawaii Gov. Josh Green said in a video statement Sunday evening.

Cadaver-detecting dogs have begun searching the burn zone but had been able to cover only about 25% of the area by Tuesday, officials said. Green said an additional 20 dogs and 35 members of a specialized urban search-and-rescue team were headed to the island and the "harrowing" scene. He said the state's dentists will also be helping with identification.

About 13,000 people lived in Lahaina, and thousands more were staying in hotel rooms, Air BnBs and other short-term rentals. Some estimates show more than 1,000 people are missing or unaccounted for, and officials have asked their relatives to submit DNA samples to help with identification.

Among those assisting in finding and identifying the dead are members of a special federal Disaster Mortuary Operational Response Team, deployed by the Department of Health and Human Services. Other search-and-rescue teams from the mainland United States, including Colorado, Los Angeles and Indianapolis, have been sent and are picking their way through downed power lines, melted cars and collapsed buildings.

About 2,700 structures were destroyed by the Aug. 8 fire, and each must be carefully searched after being assessed for safety. Authorities have warned people in the burn areas to avoid falling debris and air contaminated by heavy metals and toxic ash. No official fire cause has been released.

Among those now searching Lahaina is Colorado-based K9 cadaver dog Beta, a Belgian Malinois, who is part of the state's Task Force 1 team. There are 28 such urban search-and-rescue teams around the country, operating under FEMA command during national emergencies.

Bob Olme, program manager for Colorado's team, said giving closure to survivors is a key part of the work. Olme, a firefighter, was a deputy coroner and funeral director for 20 years. He said searchers know they carry a solemn burden.

"Those people are going to push every day to the limit of the dog, to the limit of the person, to make as many complete searches as they can, so they can begin to alleviate those families' anguish," he said. "It's so important to have closure. Even though the news you may have to deliver is tragic, to not have closure can be worse."

Olme said the toxic air poses a risk to handler and dog alike, citing burned garden pesticides and common household cleaners as concerns. Many searchers are wearing N-95 masks to protect themselves from airborne contamination.

"Unfortunately, the K9 is probably the most exposed," he said. "They depend on their sense of smell to work, so they are taking in any of these toxic substances as they do their searches every day."

In major disasters like this one, the number of dead can overwhelm local officials, from the emotional toll of the disaster itself to the logistics of storing, identifying and then releasing to families the recovered remains. Maui County typically handles about 1,400 deaths a year, according to state records.

The federal "DMORT" team usually assists local authorities by providing additional staffing to help collect DNA samples from family members of the missing, make death determinations, and conduct forensic dental exams.

Though dental records are often the first choice for identification, especially in a time when many are stored and available electronically, rapid DNA tests can provide matches within 30 minutes, according to experts.

Across Lahaina, searchers are literally sifting through the ashes, separating human remains from other debris.

"The whole process is as respectful as it can be," said Christopher Schmidt, director of the Bioarchaeology Lab at the University of Indianapolis and author of the book "The Analysis of Burned Human Remains."

Schmidt said house fires can burn at up to 2,000 degrees, which makes it impossible in some cases to visually identify a victim, a mistake no one wants to make. Just finding a body in a house where someone lived alone isn’t enough, or finding a body that’s the correct sex and height. Searchers with cadaver dogs will usually first search an area for bodies; then experts will step in to investigate further.

"We've done cases where they find their wallet in their pocket and we still do something to confirm," Schmidt said. "You never know if someone picked up someone else's pants or stuffed something in their pocket as they were running out the door."

Though searchers are deeply aware that families want to know what happened to their loved ones, they won’t rush the process.

“It may take a while because going through debris takes time and fire does highly modify structures,” Schmidt said. “Everyone’s doing the very best they can. No one’s going to rush through this.”

Marin Pilloud, formerly a forensic anthropologist with the Defense POW/MIA Accounting Agency, said this kind of work requires special training and experience, including being able to recognize the 206 bones that make up a human body. Pilloud is now a professor of forensic anthropology at the University of Nevada in Reno.

"Sometimes drywall from a house can look like bone. So it’s critical to have someone who is highly trained in the identification and discovery of human remains," she said. "You want to recover the entirety of the human remains so the families can have that closure knowing that they have all their loved ones."

Like Olme and Schmidt, Pilloud said the process is purposefully slow and methodical, and workers are constantly aware of the weight of their efforts.

“It’s tough to see such sadness," she said. "I try to focus on the good that we’re doing: We're providing a service to the community ? we're helping bring someone back to their families and give them closure.”

This article originally appeared on USA TODAY: Maui fire victims: The 'harrowing' search to ID Hawaii's dead