Below the H-1 viaduct Wednesday morning, a kiawe-fueled fire burned below thousands of commuters — a daily event that has some Oahu lawmakers concerned about the possibility of a disaster under Honolulu’s highways and bridges.

Uncounted fires — often fed by compressed propane and camping fuel — burn in illegal homeless encampments morning through night across Oahu.

Worries about fires beneath Oahu’s highways and bridges have grown after a homeless man in Atlanta was charged with arson and other crimes for allegedly setting a blaze on March 30 that triggered the dramatic collapse of a well-traveled section of Interstate 85, leading to gridlock.

According to media reports, Basil Eleby, 39, has limited mental abilities and an extensive criminal background. On March 30, Eleby allegedly put a chair on top of a shopping cart and set it on fire while smoking crack cocaine during the rush-hour commute.

The fire ignited construction materials that eventually triggered an explosion that brought down the elevated section of I-85. No one was injured.

Councilman Joey Manahan represents an area that includes the airport viaduct and nearby Iwilei, where he regularly sees fires burning amid wooden pallets and pressurized fuel containers.

“It is very dangerous,” Manahan said. “It’s a huge concern.”

“Underneath the viaduct, especially, I see people burning their garbage to try to dispose of it,” Manahan said. “These fires, if left unattended or if they haven’t been put out properly, can certainly spread throughout an encampment pretty quickly given the amount of pallets and other flammable materials and accelerants that we’ve found underneath the encampments at the Nimitz viaduct and in Iwilei.”

Following the I-85 collapse, Hawaii’s Department of Transportation reminded its inspectors and staff who work in offices and base yards below DOT bridges “to be mindful of identifying potential hazards during their daily operations.”

Officials in Georgia have been quoted as saying the I-85 fire spread to high-density polyethylene pipes and fiberglass conduits that were stored there.

Locally, the DOT said it keeps concrete barriers and items discarded along roads but “does not store HDPE pipes or fiberglass under our viaducts,” according to a statement.

In 2016, the Honolulu Fire Department responded to seven rubbish fires near North Nimitz Highway by the H-1 offramp, HFD Capt. David Jenkins said. No damage or injuries were reported.

The source of the fires, Jenkins said, was “typically garbage bags, plastic bags, maybe some pallets but not a high volume of material.”

Jenkins emphasized that it’s “irresponsible” to blame the homeless themselves for fires in and around where they live.

“That may not necessarily be so,” Jenkins said. “There have been times where homeless tents were burned out and it wasn’t due to the residents there. It was outside sources that started the fire with a criminal intent, trying to burn out the homeless.”

An Iwilei resident sent Manahan a dramatic photo of a fire that broke out in a homeless encampment along Iwilei Road in the early hours of April 2. The resident told Manahan that the fire was accompanied by an explosion.

The flames reached four stories high, Manahan said, and spread to nearby tents.

“Everything caught fire real quick,” Manahan said. “A lot of the encampments are using these pallets that are very, very flammable. It’s almost ideal conditions for starting a fire.”

Several homeless people living below the viaduct burned open fires Wednesday morning but said they are always careful and the fires pose no danger.

Like others, Jimmy Bedan, 53, said he’s more worried that new fears about fires below the viaduct will lead to more sweeps.

“I’m worried about getting kicked out,” Bedan said, echoing the sentiment of his neighbors.

Nearby, Dianah Paglinawan shredded carpet padding into three piles, which she then ignited to ward off flies.

“They’re real bad,” she said of the flying pests.

Paglinawan said she does not live under the viaduct and was only watching two tents for a friend, whom she said had been arrested on suspicion of auto theft.

There is no simple way to control fires in illegal encampments, Manahan said.

Trying to impose some sort of fire code certainly wouldn’t work for people who are already living illegally on public land, he said.

“They’re not going to meet the fire code,” Manahan said. “They’ve got all of these pallets that allow air through, almost like a perfect condition for a fire. Some guys are using liquid propane to cook. But you never know what folks are keeping in their dwellings that are flammable, as well.”

Across the island in Wahiawa, state Rep. Marcus Oshiro (D, Wahiawa- Whitmore-Poamoho) said he worries what a fire in a homeless encampment could do to the Karsten Thot and Wilson bridges.

The bridges “are the lifeblood for Wahiawa and the North Shore,” Oshiro said. “A few reckless individuals starting a fire can lead to just unimaginable damage and destruction.”

Last month, Oshiro helped organize a cleanup of the encampments below and around the Karsten Thot bridge.

Volunteers, most of them homeless, carried out enough trash to fill four dumpsters. Another three to four dumpsters’ worth of rubbish — sitting right next to the bridge — still has to be bagged and hauled away.

Most of it belonged to just one person who moved in about nine months ago and burrowed his way into the trash to carve out a home, Oshiro said.

“It’s one of those homeless individuals that has severe mental deficiencies,” Oshiro said. “We can’t compel someone like that to receive services.”

At its peak, the mountain of trash stretched for 50 yards and reached 20 feet high, Oshiro said.

Volunteers pulled out “hundreds” of empty plastic containers that once held motor oil and could have fueled a fire that would have been toxic, Oshiro said.

If a fire broke out inside the mound, it could have smoldered for days before breaking into an inferno that would have threatened California grass next to the bridge — “the perfect stock for a brush fire,” Oshiro said.

“It could have catastrophic effects,” he said.

Mike Saballa, 64, has been living on the North Shore side of the bridge for 10 years and pulled out “gas cans, empty motor oil cans” during last month’s cleanup.

He insisted there was no danger of a fire or explosion damaging the bridge.

“It’s not going to blow up,” he said dismissively.

Saballa said the homeless who live around the bridge are mostly responsible and “work hard to clean up the area.”

He also has a self-interest in trying to ensure no fires break out.

“When something goes wrong,” he said, “we have to move.”