On June 30, 2013, Arizona’s infamous Yarnell Hill Fire overran the Granite Mountain Hotshots, killing 19 firefighters as they crouched beneath their woefully inadequate aluminum shelters.

The tragedy was nearly as mysterious as it was horrific: Minutes earlier, Granite Mountain had been stationed in the secure “black,” already-burned land that couldn’t reignite. Why the hotshots abandoned safety is a question that has spawned two official reports, hundreds of articles and countless Internet-fueled conspiracy theories. Was it incompetent leadership? Hubris? Or a reasonable decision rendered disastrous by a sudden shift in the wind?

Kyle Dickman’s new book, On the Burning Edge, doesn’t provide a definitive answer, but it’s the best account yet of the Yarnell catastrophe. Dickman, a contributing editor at Outside Magazine and a former firefighter, is concerned less with how Granite Mountain’s men died than with how they lived. Burning Edge offers an intimate window into the singular culture of hotshots, the men and women who defend America’s public lands with chainsaws, axes and an endless supply of prepackaged meals and chewing tobacco.

Granite Mountain’s members, most of whom are in their 20s, are a study in contradictions: Testosterone-driven in the field and tender at home, hard-drinking and yet eager to join hands and pray “in the soft glow of the dying fire.” We meet Scott Norris, a mentor to younger hotshots who bonds with his girlfriend over their mutual affinity for handguns; Grant McKee, an aspiring paramedic lured by good pay and repulsed by the team’s hazing rituals; and guilt-wracked sole survivor Brendan “Donut” McDonough, a third-year hotshot “with the crew’s longest rap sheet and foulest mouth.” The most complex character is Eric Marsh, the ambitious superintendent who moves his team away from safety and toward the fire’s path—perhaps, Dickman speculates, to impress higher-ups. To some firefighters, Marsh’s mistake was understandable; to others, it was an “egregious and unforgivable error in judgment.”

Still, no one man led the Granite Mountain Nineteen to their deaths. Burning Edge provides a deft synopsis of a century of firefighting malpractice, from the nascent Forest Service stamping out all fires to save valuable timber, to the ascent of the anti-fire mascot Smokey Bear, whose “fame rivaled that of Santa Claus.” By interfering with natural cycles, forest managers permitted brush and saplings to choke meadows, creating a “ladder of fuels” that help low-intensity conflagrations climb into treetops and become mega-fires.

Not until one-third of Yellowstone National Park burned in 1988 did America’s public-land agencies recognize the folly of knee-jerk suppression. Even today, however, firefighters extinguish 98 percent of blazes in their early stages. Though Dickman devotes a few pages to contemporary fire policy, he rarely pulls back to analyze the larger land-use trends that put hotshots in harm’s way, particularly population growth in the wildland-urban interface and landowners who fiercely decry building codes even as they demand that the federal government ride to their rescue. Climate change, which is making the West hotter, drier and more flammable, casts an omnipresent shadow over Burning Edge, but earns little explicit mention in its pages.

In the end, this is a book not about the scientists who study fire, nor the wonks who manage it, but about the grunts who face the consequences. Jesse Steed, GraniteMountain’s captain and an ex-Marine, called hotshotting “the next best thing to the military,” and the parallels are unmistakable: There’s the grueling training, the obsession with equipment, the interminable deployments, the special camaraderie. As Dickman retraces the crew’s final weeks, we eavesdrop on our protagonists in their most private moments: Kevin Woyjeck dancing in the backseat of McKee’s car, Norris slipping away from camp to steal one last shower with his girlfriend, and so on. Knowing the fate that awaits these young men makes their precious happiness almost unbearable; as June 30 draws ever closer, turning the pages starts feeling downright cruel.

When the Granite Mountain hotshots finally reach Yarnell, they’re greeted by “total nonstop chaos.” Three-mile walls of fire roar through the chaparral, and “dozens of propane tanks (send) columns of flames shooting into the air like fires off an oil derrick.” Communications deteriorate as hotshot crews, agencies and commanders tussle for control of radio frequencies. Airplanes and helicopters nearly collide. Granite Mountain, trapped in a canyon, tries desperately to hail air support, which fails to grasp the crew’s predicament until it’s too late.

The Yarnell Hill Fire may have been sparked by lightning, but it was partly a manmade calamity, exacerbated by uncertain hierarchies, miscommunications and breaches in safety protocols. If these 19 deaths accomplished nothing else, perhaps we can use them to improve how the West’s firefighting agencies interact on the line—because more, and bigger, fires are on the way.

This review originally appeared in High Country News.

On the Burning Edge: A Fateful Fire and the Men Who Fought It

By Kyle Dickman

Ballantine Books

304 pages, $26