The death toll from the Maui wildfires have reached 93 making it the deadliest US wildfire in more than a century - and the total is likely to rise in coming days as search teams with cadaver dogs continue sifting through the ruins of Lahaina.
The scale of the damage came into sharper focus, four days after a fast-moving blaze levelled the historic resort town, obliterating buildings and melting cars.
The cost to rebuild Lahaina was estimated at $US5.5 billion ($A8.5 billion), according to the Federal Emergency Management Agency (FEMA), with more than 2200 structures damaged or destroyed and more than 850 hectares burned.
Hawaii Governor Josh Green warned at a press conference the death toll would continue to increase as more victims were discovered. Dogs trained to detect bodies have covered only three per cent of the search area, Maui County Police Chief John Pelletier said.
Officials vowed to examine the state's emergency notification systems after some residents questioned whether more could have been done to warn them before the fire overtook their homes. Some were forced to wade into the Pacific Ocean to escape.
Sirens stationed around the island - intended to warn of impending natural disasters - never sounded, and widespread power and cellular outages hampered other forms of alerts.
The state's attorney general, Anne Lopez, said she was launching a review of the decision-making before and during the fire, while Green told CNN he had authorised a review of the emergency response.
Officials have described a nightmarish confluence of factors - including communications network failures, wind gusts of up to 130km/h from an offshore hurricane and a separate wildfire dozens of miles away - that made it nearly impossible to coordinate in real time with the emergency management agency that would typically issue warnings and evacuation orders.
"Over time, we'll be able to figure out if we could have better protected people," said Green. He said the multiple fires and dangerous winds created extraordinarily difficult conditions.
The death toll made the inferno, which erupted on Tuesday, Hawaii's worst natural disaster, surpassing a tsunami that killed 61 people in 1960, a year after Hawaii became a US state.
The latest figure exceeded the 85 people who perished in a 2018 fire in the town of Paradise, California, and was the highest toll from a wildfire since 1918, when the Cloquet fire in Minnesota and Wisconsin claimed 453 lives.
Officials have secured 1000 hotel rooms for people who lost their homes and are arranging for rental properties to serve as housing at no cost to families, Green said. More than 1400 people had been taken in at emergency shelters.
Deanne Criswell, the FEMA director, said the agency had 150 people on the ground and that additional search teams and dogs would be arriving within a day or two.
Authorities began allowing residents back into west Maui on Friday, although the fire zone in Lahaina remained barricaded. Officials warned there could be toxic fumes from smouldering areas and said search operations were continuing.
Hundreds of people were still missing, though a precise count was not clear.
At a family assistance centre in Kahului, June Lacuesta said he was trying to locate nine relatives who had not been heard from since Tuesday.
"When I see Lahaina town itself, I cannot describe the feelings I get," said Lacuesta, who was headed to a church shelter next to continue his search.