MAUI, Hawaii -- Maui County is suing the Hawaiian Electric Co., alleging that its negligence led to the deadliest U.S. wildfire in the past 100 years. The county suffered an estimated $5.5 billion in damages from fires in Lahaina and Kula — and it says the deadly disaster was preventable.

The civil suit filed Thursday seeks a jury trial. It targets Hawaiian Electric, or HECO, and several related companies, seeking "punitive and exemplary damages" and to recoup costs and loss of revenue from the fires.

HECO is a publicly traded company that accounts for 95% of Hawaii's electricity customers. The utility tells NPR that it is "very disappointed" that the county filed suit.

The exact cause of the fires in Maui is being investigated by federal officials. But dozens of Hawaiian Electric's poles and energized lines were felled by high winds that propelled the fire. Videos posted on social media appeared to show power lines starting fires, and experts have indicated they think the power lines were likely a major factor.

The utility didn't have a plan to cut power, county says

Maui County accuses HECO and its subsidiaries of two major failures: not properly maintaining the electrical system and power grid; and "failing to power down their electrical equipment despite a National Weather Service Red Flag Warning on August 7th."

The county says the utility should have had a plan to cut off electrical power when conditions get dangerous.

"The practice of deenergizing power lines during fire weather conditions is common in the Western United States," the lawsuit states. It notes that large utilities in wildfire-prone California have implemented "Public Safety Power Shutoff" plans to prevent fires during high-risk conditions.

"Defendants never created a PSPS plan," the suit states.

Survivors of the fire in Lahaina have also said downed poles and wires slowed them down as they tried to flee what became a deadly calamity, saying their path to safety was obstructed by utility trucks in the roads.

HECO has said it's controversial to cut off power

In an emailed statement to NPR about the county's lawsuit, Hawaiian Electric emphasized that its focus has been on supporting "not just the people of Maui, but also Maui County."

"We are very disappointed that Maui County chose this litigious path while the investigation is still unfolding," the company added.

When Hawaiian Electric's President and CEO Shelee Kimura was asked last week why the company didn't shut off power when winds picked up, she said PSPS plans are controversial.

Kimura said the programs require coordination with first responders, and that they could also pose a risk to vulnerable people with specialized medical equipment.

The utility will conduct its own investigation of the fires, she said.

Maui County's lawsuit was filed in the Second Circuit Court in Wailuku.