Wildfires tore through the Hawaiian island of Maui, killing at least 55 people and charring parts of the island. The historic town of Lahaina, a popular tourist destination, has been devastated.
The exact cause of the three fires that started earlier this week hasn’t been determined. Maj. Gen. Kenneth Hara of Hawaii’s Department of Defense said the fires were fueled by dry conditions, low humidity and high winds.
Here’s a look at some of the contributing factors behind the deadly blazes.
High winds
Winds from Hurricane Dora, a Category 4 hurricane spinning nearly 800 miles southwest of Honolulu, fanned flames on the island.
Between Monday and Wednesday, Maui had peak winds ranging from 45 miles an hour to 67 mph, according to the National Weather Service. Winds were still strong Thursday, at about 30 mph to 50 mph.
Authorities said they had prepared for the hurricane but not the fires that followed.
Firefighters working on the blaze in the Lahaina area had declared the fire 100% contained Tuesday morning, but it flared up by the afternoon.
The weather service had issued a Red Flag Warning, which indicates extreme fire risk, across parts of all Hawaii islands until Wednesday at 6 p.m. local time.
Dryness
The western part of Maui, where the fires raged, was in a severe drought because of a lack of rain, said Greg Carbin, the chief of forecast operations at the National Weather Service’s Weather Prediction Center.
“That’s the one spot that was quite dry and drier than the other islands,” said Carbin.
At least 1,000 acres of Maui’s Upcountry, an agricultural inland area that includes Haleakala National Park, have been charred.
Local topography
The island is made of two volcanoes, several mountains and steep valleys, with flat land along the ocean.
Winds coming off the ocean grew faster on land, fanning the flames. That’s because a layer of warm air in the atmosphere, called an inversion, was lower than usual, said John Bravender, a meteorologist at the National Weather Service in Honolulu. As winds headed to the mountaintops, they got trapped between the ground and the inversion and pushed downward, accelerating their speed.
“It’s like putting your finger over a hose,” he said. ”That restricts the flow and makes it go faster.”
Local fire officials alerted residents on just how quickly the blaze moved.
“The fire can be a mile or more from your house, but in a minute or two, it can be at your house,” Fire Assistant Chief Jeff Giesea said in an alert Tuesday.
Some people jumped into the waters off Lahaina to flee flames, which have damaged or destroyed hundreds of buildings in the historic former capital of the Hawaiian Kingdom.
A decline in farming is raising the risks of wildfires, according to Clay Trauernicht, a fire specialist at the University of Hawaii at Manoa. Lands once used to grow pineapple or sugar cane are now filling up with waist-high grass that isn’t native to Hawaii, he said. Without rain, the grass dries out rapidly and is flammable.
“When it ignites, you get this explosive growth of fire,” said Trauernicht. “It’s incredibly dangerous.”