The Maui Fire Department is expected Wednesday to explain exactly how the deadliest U.S. wildfire in more than a century was sparked last year.

The historic Maui town of Lahaina was destroyed and 102 people were killed the disastrous wildfire. Several agencies have investigated the fire, detailing the poor conditions — including hurricane-force winds and emergency response missteps — that contributed to the tragic outcome. But so far, those reports have stopped just short of analyzing the fire’s origin and cause, leaving that to the Maui Fire Department and the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives.

The Maui Fire Department asked the ATF to help with the cause and origin investigation last year, and the ATF’s findings will be included as an appendix to the department’s report.

What is already clear: Many things went wrong before and during the disaster. The National Weather Service gave advance warning that a hurricane passing far offshore would bring strong winds to the island, dramatically raising the fire danger. But an investigation by the Fire Safety Research Institute for the Hawaii Attorney General’s office found “no evidence” that officials prepared for the fire danger despite the warning.

A Hawaiian Electric power line fell early on the morning of Aug. 8, sparking a fire in overgrown brush near the edge of town. Fire crews responded and stayed for several hours until they believed the fire was extinguished. After they left, flames were spotted again and though firefighters rushed back, they were no match for the wind and flames.

Communication between the police and fire departments was spotty, cellphone networks were down and emergency officials did not activate the emergency sirens that might have warned residents to evacuate. Power lines and poles had fallen in many locations throughout town, and police blocked some roads to protect residents from potentially dangerous power lines. First responders also had trouble getting a firm answer from Hawaiian Electric representatives if the power had been cut to the area.

The blocked roads contributed to gridlock that left fleeing people trapped in their cars as the flames advanced. Others died in their homes or outside as they tried to escape. The death toll surpassed that of the 2018 Camp Fire in northern California, which left 85 dead and destroyed the town of Paradise.

In the months since, thousands of Lahaina residents have sued various parties they believe to be at fault for the fire, including Hawaiian Electric, Maui County and the state of Hawaii. The defendants have often tried to point fingers at each other, with Hawaiian Electric saying the county shouldn’t have left the first fire unattended, and Maui County contending the electric utility failed to take proper care with the power grid. Exactly who was responsible for clearing brush and maintaining area has also been a point of contention among the defendants, along with the utility’s lack of a public safety power shut-off program.

A few days before the one-year anniversary of the wildfires, Hawaii Gov. Josh Green announced a $4 billion settlement. That’s the amount the defendants — including Hawaiian Electric, the state, Maui County, large landowners and others — have agreed to pay to settle claims.

But the deal is tied up in court, awaiting a decision from Hawaii Supreme Court on whether insurance companies can go after the defendants separately to recoup what they’ve paid to policyholders. Lawyers for people seeking compensation fear allowing insurance companies to sue Hawaiian Electric and others will subvert the deal, drain what is available to pay fire victims and lead to prolonged litigation. ___

Boone reported from Boise, Idaho.