The day California’s deadliest-ever wildfire erupted, about 2,000 state employees responded to the blaze. Among them were more than 500 prison inmates.

That morning a year ago, a familiar alarm cut through the sounds of breakfast at the Ishi Conservation Camp, a specialized prison in northern California that trains inmates to fight fires on foot. There are 44 such “fire camps” across the state, run jointly by the Department of Corrections and Cal Fire, the Department of Forestry and Fire Protection.

“It wasn’t no big deal,” said a 22-year-old inmate at the camp, who shared his story on condition of anonymity. “We all got rushed out of breakfast.”

Nobody anticipated that they were about to head into the worst wildfire the state had ever seen.

The Camp Fire first flared in the northern Sierra Nevada foothills early Nov. 8, 2018 and rapidly spread to the nearby town of Paradise. By the time it was finally contained nearly three weeks later, 85 people were dead.

For the inmates at Ishi, even before the Camp Fire, it had already been a particularly intense season fighting sizable blazes in the area, Cal Fire Capt. Luke Thomas told FRONTLINE for the film Fire in Paradise.

“We had been on the road most of the summer,” said Thomas, Ishi’s camp operations captain, who has worked with inmate firefighters for the past seven years. “So by the morning of Nov. 8, I wasn’t really anticipating what we were about to see.”

Outside, it was cool and windy. The inmates stood in line, waiting for roll call.

The inmates at the camp are all transfers from other prisons, who must have “minimum custody status,” based on their behavior while incarcerated. The program doesn’t allow inmates convicted of certain offenses such as sexual offenses, arson or any history of escape with force or violence. They are trained to the standard of Cal Fire’s entry-level seasonal firefighters. In 2016, inmates in the program outnumbered California’s seasonal firefighters more than two-to-one, according to Cal Fire.

After roll call, about 30 inmates from Ishi Conservation Camp were organized into a single strike team, Thomas said. As they left camp in two buses, they could see a column of smoke forming over Paradise, about an hour’s drive away.

“We realized that we were gonna have our work cut out for us,” Thomas said.

The crew buses approached Paradise from the south using Pentz Road, one of four main routes into town. They passed heavy outbound traffic, as the community of 26,000 people fled smoke and flame.

They pushed further into the smoke and it was like “the lights went out,” Thomas said. Soot and ashes obscured the morning sun.

“It became as black as the blackest night you’ve ever seen,” he said.

Their first glimpse of flames were spot fires, patches that burn beyond the main blaze. The crews prepared to unload. They couldn’t yet see the main fire, but the 22-year-old inmate, who’d just been called from his breakfast, remembers an orange glow through the smoke. His heart began to pound.

“Like a glow everywhere, really, it’s like all … it’s all aglow,” he said. “And you hear the crackling from the wood and the trees popping.”

California’s inmate firefighters are trained as hand crews, hiking into terrain too rough or steep for vehicles to reach. There, they control spot fires or try to hem in the fire by cutting away anything that can burn from the fire’s edge to form what’s known as “hand line” or “fire line.”

“We don’t have water, we’re not a fire engine,” Thomas said. “We’re basically designed to be able to travel long distances on foot, constructing fire line in the steep, tough, rugged ground where the bulldozers can’t get.”

Though hand crews don’t fight fire with water, they do carry chainsaws to cut down fences and clear brush. They can travel more than a dozen miles per day while working “in extremely remote places,” Thomas said. The day the Camp Fire hit Paradise, they instead faced burning buildings and a chaotic evacuation.

“I’ve been doing this for 17 years, and I was scared,” Thomas said.

Inside the crew buses, the inmate firefighters paused to pray – a routine to “stop our jitters, our nervousness,” one of the men told FRONTLINE. He asked not to be identified by name, though he agreed to an on-camera interview.

When he stepped outside, his eyes smarted and the air – heavy with the smell of scorched tires and wood – scratched his throat. All around, he could hear a high-pitched crackling.

Depending on their conviction, inmate firefighters typically receive up to two days off their sentence for every day spent in the program. Inmates with violent convictions receive one day off their sentence for every day in the program, as do inmates in support roles such as cooks and laundry workers. They are paid up to $5.12 per day, depending on their position and skill level, with an additional $1 per hour while fighting fires. The state in March increased the pay from an average of $2 per day.

“Some of these guys have been on my crew for three, four years,” said Thomas. “They’re a huge asset to us.”

Within minutes of deploying the crews, Thomas said he realized chasing spot fires wouldn’t be enough. Paradise residents were struggling to escape the blaze.

The team pivoted to the escape effort, evacuating houses and loading cars. They worked through the morning, regrouping once the area had mostly emptied of people. Then they drove farther south, along the edge of town, to an intersection that lead into the heart of Paradise.

Ahead, Thomas could now see the main blaze. Stranded vehicles lined the street.

“There was still multiple people down there,” Thomas said. “At that point, we had decided that itprobably wasn’t going to be too smart of us to try to drive our big buses … down in there.”

The men left behind their crew buses and instead continued on foot.

“We continued down and there was still people trying to load their belongings as their house is on fire,” Thomas recalled. “The main fire was really getting on us.”

Still, Thomas said he assessed their location as safe, as long as they maintained an escape route. They walked further into town, where they encountered a clog of abandoned vehicles. Behind the blockade, trapped in traffic, Thomas could see Paradise residents sheltering in their cars.

“We went on foot down there to kind of try to get whoever we could out,” he said.

A distinctive sound suddenly cut through the crackling of flames – “the clinking, clacking of a dozer coming down the road,” Thomas said. “And he actually cleared those vehicles that were blocking the road.”

With traffic now flowing, the inmates hiked back toward the intersection where they had left their crew buses. They would work late into the night, clearing brush and protecting what buildings they could from the fire’s onslaught.

Under the terms of the program, the inmate firefighters work for 24 hours, before rotating with a fresh crew. They then receive a day-long break.

Overall, about 770 inmates from 21 different fire camps were among the 5,600 Cal Fire personnel assigned to contain the Camp Fire. The fire burned for 17 days and destroyed more than 18,500 structures, including homes and businesses, the agency said.

Half of California’s 20 most destructive fires have occurred in the last four years. As the severity and frequency of wildfires increase, inmate hand crews have become an ever-more valuable tool for the state, said Chief Thom Porter, the director of Cal Fire.

“We don’t put fires out until we put boots on the ground,” Porter said. “With our inmate program, that’s one way that the state has found to really increase the numbers of people that we can put on a fire in a very proactive way.”

Porter says injuries are rare, though two inmate firefighters and their fire captain suffered serious burns on the first day of the Camp Fire, according to a Cal Fire report. At least three inmates – two men and one woman – have died over the past three years while working in the program.

When not responding to emergencies, the crews are a source of low-wage work for fire-prevention tasks such as clearing brush and fallen trees.

Once inmates leave the program, their criminal records may stand in the way if they want to continue fighting fires. California law prevents most people with felony convictions from becoming professional firefighters.

Earlier this year, California’s legislature did introduce a bill that would mark a first step toward making it easier for people with felony convictions to become firefighters. But the bill – rather than proposing legislation – declares only an intent by the legislature to eventually enact laws under which former inmates can become firefighters.

The state has been criticized by criminal justice advocates, including the ACLU, for using prison labor to fight fires. Some suggest California places more value on its supply of inmate firefighters than on reforms or other types of early release programs.

The state says its firefighter program is an opportunity for inmates to do meaningful work while incarcerated. And Porter points out the 3,100 men and women in fire camps across the state represent only a fraction of the overall prison population. He adds the inmates who qualify for fire camps tend to be the same men and women who are eligible for early release. As a result, the state is constantly recruiting new candidates, and has even started accepting county inmates into the program.

“We are doing everything we possibly can to increase the population of our inmate programs,” Porter said. “We’ve had numerous release programs that have reduced sentences and gotten inmates out of prisons … it’s reduced the number of inmates that we have available to us to put on our crews and we are working to recover those numbers.”

Ultimately, California’s incarcerated men and women have a choice about whether they want to apply for the program. But the promise of a dramatically shorter sentence is hard to resist, said the firefighter who recalls praying in a crew bus before stepping into the Camp Fire.

The work “has its moments,” he said – but really, “it’s either do this to get home to your family earlier or be back on the yard doing something else. I’d rather get back to my family.”