A U.S. Department of Justice fire investigation team is in Hawaii to determine the origin and cause of the Lahaina wildfire that killed more than 110 people and destroyed the 5-square-mile heart of town.

The Bureau of Alcohol, Tobacco, Firearms and Explosives’ National Response Team arrived from the ATF’s Honolulu Field Office and the Seattle Field Division on Thursday to help Maui firefighters and other partners figure out what sparked the fast-moving fire that destroyed homes and businesses and left an estimated 1,000 people unaccounted for.

The ATF team joins Federal Bureau of Investigation agents who are working with Maui police to find missing persons and identify people killed in the Lahaina fire.

The FBI is helping collect DNA samples from family members of those who are unaccounted for.

Maui Mayor Richard Bissen said Thursday that crews combing through the ruins of Lahaina looking for victims of the Aug. 8 firestorm have searched about 45% of the burned-out 5-square-mile area.

In an interview with CNN, Bissen thanked the FBI for assisting in the search for the missing by analyzing cellphone data, and he said over 200 personnel with 40 cadaver-detecting dogs were searching the rubble.

“It is standard practice for the FBI to assist our law enforcement partners, in this case Maui PD, as we have various tools and personnel that can assist in locating and identifying those persons who are still unaccounted for,” said Josephine van der Voort, an FBI spokesperson.

The ATF’s team will include one electrical engineer from the ATF Fire Research Laboratory, two Certified Fire Investigators, a CFI candidate from the Honolulu Field Office, and one Arson and Explosives Group Supervisor from the Seattle Field Division, according to a news release.

“We were all devastated to learn of the loss of life and property on Maui from the Hawaii wildfires,” ATF Seattle Field Division Special Agent in Charge Jonathan T. McPherson said in a written statement. “We hope the deployment of National Response Team resources will allow the residents of Maui, and the state and nation as a whole, to know that we will do everything in our power to support our local counterparts in determining the origin and cause of the wildfires there, and hopefully bring some healing to the community.”

This is the 21st NRT activation this fiscal year and the 910th since the program began in 1978, according to the release.

The NRT team provides an immediate and sustained nationwide response capability, “typically deploying within 24 hours of notification, with state-of-the-art equipment and highly qualified ATF personnel specializing in fire origin and cause determination.”

The NRT most recently helped with the Grande Costa D’Avorio ship fire investigation in July at Port Newark in Elizabeth, N.J., and the Nashville Christmas Day bombing.

The team was also on the ground after the Sept. 11, 2001, attack on the Pentagon, and bomb attacks on the Centennial Olympic Park in Atlanta in 1996, the federal building in Oklahoma City in 1995 and the World Trade Center in 1993.

News of the the DOJ’s involvement in the investigation came after the state attorney general earlier Thursday announced the hiring of a third-party private organization with experience in emergency management and processes to “assess the performance of State and County agencies in preparing and responding to the Maui wildfires,” according to a news release.

“This will be an impartial, independent review,” state Attorney General Anne E. Lopez said in a statement. “Having a third-party conduct the review will ensure accountability and transparency and reassure the people of Hawaii that all of the facts will be uncovered. The information collected will be used to assess the performance in emergency preparedness as we are constantly looking for ways to improve. We intend to look at this critical incident to facilitate any necessary corrective action and to advance future emergency preparedness.”

Lopez declined a Honolulu Star-Advertiser request for an interview.

The review is not an official criminal or civil investigation, Gov. Josh Green clarified Wednesday.

Green asked Lopez to conduct a “comprehensive review of critical decision-making, policies, and the actions taken,” so that he and state officials can focus on the recovery efforts, according to the release.

This is likely to be a “months-long effort” and the attorney general’s office did not disclose whether it would be a bid process to award the contract to the third party. No cost estimate for the review was immediately available.

“We will be taking the necessary time to follow the facts wherever they lead,” said Lopez.

State Sen. Jarrett Keohokalole, who co-authored a letter calling for the third-party review, said in a statement that an “independent review will ensure that all aspects of the incident, including any potential shortcomings in preparation, response, and communication, are thoroughly examined.”

“By entrusting this process to an unbiased entity, we can collectively ensure that lessons are learned, best practices are identified, and that our communities are better equipped to face similar challenges in the future,” said Keohokalole.