It is unclear how many people have lost their lives in Lahaina as authorities in Hawaii near the end of their search for dead.

HONOLULU (AP) — Crews in Hawaii have nearly finished searching for victims of the deadliest wildfire in the United States in more than a century, authorities said Tuesday, and it’s unclear how many people perished.

Three weeks after the fire devastated the historic beach community of Lahaina, Maui, the death toll stands at 115. But an unknown number of people are still missing.

Officials have suggested responders have likely already recovered any recognizable remains, and are shifting their response to focus on removing hazardous waste and making the area safe so residents can start returning.

“We have nearly completed the search and recovery mission and are moving into the next phase,” Darryl Oliveira, the acting administrator for Maui’s emergency management agency, said at a news conference.

The next phase would be hazardous waste disposal led by the US Environmental Protection Agency, he said.

Maui Police Chief John Pelletier said urban search and rescue teams had “covered 100 percent of their area,” but some search activity was continuing in the ocean off Lahaina.

The FBI is searching 200 yards (183 yards) along a four-mile (6.4 kilometer) coastal strip, but no human remains have been found, he said. There are 110 missing person reports filed with Maui police, and more than 50 of them remain open cases that are still being actively processed, he said.

Although initial searches have been completed, authorities could also use details of missing persons reports to re-examine areas, he added.

“They say, ‘My loved one was here’ and that can be a data point and we can move on,” Pelletier said. “In case there is any chance that something needs to be investigated further, we have archaeologists and we will make sure we can do it so, again, we do it the right way.”

He asked for “confidence and patience” as authorities continue to identify the remains and go through lists of the missing.

So far, authorities have identified and notified relatives of 45 of those killed. They collected DNA from 120 people to identify the dead and continue to see more samples.

EPA crews will search for and manually dispose of hazardous materials like paints, pesticides and batteries. Lahaina had a large number of lithium-ion solar energy storage batteries, which the agency will treat as unexploded ordnance, said EPA incident commander Steve Calanog.

Crews will remove large pieces of asbestos, but any asbestos in the ashes will be dealt with in the next phase of cleanup, he said.

The EPA will spray an adhesive called Soiltac on the ash to prevent it from migrating into the ocean, Calanog said. The substance is “non-toxic, biodegradable and harmless to the marine environment” and will degrade in two to three months, he said.

The EPA has embedded about 25 cultural observers on its teams so that the agency “acts with caution, reverence and respect” in the city that was the capital of the ancient Hawaiian kingdom in the 1800s and the residence of Hawaiian chiefs during centuries.

“We all know the rich and long historical and cultural significance of Lahaina,” Calanog said.

The EPA said in a press release that it would take up to several months to remove the household hazardous materials, although the work could be completed sooner.

Maui County did not sound its emergency sirens to warn residents of the fire when it spread Aug. 8.

Darryl Oliveira, who took over as acting administrator of the Maui Emergency Management Agency on Monday, said sirens had never been used for wildfires in Hawaii before. But he said Maui, the state and other counties in Hawaii are working on new protocols to do this.

“We see huge interest in integrating more tools into our arsenal to keep the public informed and provide them with early warning,” he said, adding that the current hurricane season straddles extremely dry conditions in Maui and throughout the state.

In an early example, authorities sounded emergency sirens on Saturday to warn residents of a bushfire near Kaanapali hotels in Lahaina. Firefighters quickly brought the blaze under control.

Oliveira guided the Big Island through hurricanes and volcanic eruptions as Hawaii County Civil Defense Chief for many years.

He said one of the challenges was educating the public – including tourists – on what to do if they heard the sound of a siren to warn of a wildfire.