Matthew McConaughey in Tense Wildfire Thriller

Few if any filmmakers can build and breathlessly sustain visceral intensity with the command of Paul Greengrass, who brings documentary realism, kinetic energy and heart-pumping adrenaline to stories drawn from life or fiction, generally about people caught in explosive situations. The Brit director is a master of chaos. That makes him an ideal fit for The Lost Bus, which plunges us into the 2018 inferno that ripped through Northern California’s Butte County, decimating entire communities. If the human drama is seldom as alive as the flames, that’s no fault of the fine leads, Matthew McConaughey and America Ferrera.

About those flames: Greengrass, DP Pål Ulvik Rokseth (who shot the director’s riveting 2018 lone-terrorist film 22 July) and an ace visual effects team led by Charlie Noble give the wildfire the qualities of an unrelenting supernatural force of destruction, without ever compromising its authenticity. The almost instantaneous spread from scattered ground fires caused by a fallen power line to an all-consuming blaze devouring everything in its path is terrifying, shooting out tongues of flame, candling trees and raining down burning embers as it grows like an uncaged monster.

Known as the Camp Fire, a name derived from its origin near Camp Creek Road, the wildfire was the deadliest and most destructive in California history, displacing almost the entire communities of Magalia, Concow and Paradise. Greengrass and co-writer Brad Inglesby (Mare of Easttown) adapted their script from journalist Lizzie Johnson’s book, Paradise: One Town’s Struggle to Survive an American Wildfire, and first-hand accounts of people who lived through the catastrophic events.

Coming less than a year after the devastating Southern California wildfires, The Lost Bus might be triggering for the many displaced people who lost their homes and businesses. But it also offers a balm in its portraits of bravery, heroism and resilience by focusing specifically on the inspiring stories of two people, bus driver Kevin McKay (McConaughey) and elementary school teacher Mary Ludwig (Ferrera).

Opening with ominous footage of electrical towers and power lines trembling in high winds, the film swiftly foreshadows the disaster with drone shots of small towns surrounded by miles of forest. Weather reports predict an uptick in wind speeds and increased risk of fires after a long dry spell.

Kevin grew up in Paradise and has only recently moved back there following the death of his father, from whom he was estranged for 20 years. Responsible for his 15-year-old son Shaun (played by the actor’s own son, Levi McConaughey) and for the medical care required by his elderly mother Sherry (Kay McCabe McConaughey, you guessed it), Kevin is desperate for overtime shifts. But Ruby (Ashlie Atkinson), the briskly efficient dispatcher at the bus depot, has nothing for him. In what seems like downbeat overkill, his sweet old dog’s cancer has spread, forcing him to have the animal euthanized.

Greengrass and his team of three editors, led by seasoned action hand William Goldenberg, cut back and forth between Kevin’s personal difficulties and reports of rapidly escalating wildfires, the scramble to control them led by Cal Fire battalion chief Ray Martinez (Yul Vázquez).

This part of the story is a compelling account of emergency management and the coordination required by firefighters, government and other organizations from across multiple counties to combat a blaze and make crucial evacuation decisions. What seems like dozens of fire trucks, air tankers and helicopters are mobilized, but strong winds allow for minimal progress.

The movie’s most sobering note is struck later when Martinez is informed that they have no more resources left to fight the fire, forcing him to announce that Cal Fire is now focused solely on saving lives.

All this happens while a representative from Pacific Gas & Electric stands around making belated offers to help after stammering out lame justifications for not shutting down faulty power lines when the weather alerts went out. Anyone infuriated about the failure to adequately address climate change and the shortcomings in national emergency preparedness will find plenty here to stoke their anger.

The movie kicks into gear when Kevin — late returning to the depot after completing his drop-offs and attempting to get fever-reducing meds to Shaun, who he assumed was faking his claims of illness the night before to get off school — responds to a call from Ruby to pick up a class of elementary school kids boxed in by fire and deliver them to a safe pickup point.

A lovely moment of humor colors the anxiety when Kevin arrives and tries to marshal everyone onto the bus to get out of there fast, while Mary maintains her caring professional demeanor by refusing to distress the kids and instead trying to keep them calm. “Say hello to Kevin, he’s our driver,” she tells the class, as if they’re heading out on a fun excursion. When she has the kids form two neat lines — smallest in the front, tallest in the back — and follow her without rushing, Kevin’s head looks like it’s about to explode.

Ferrera is wonderful here, bringing a shot of warmth, compassion and steady resolve that makes it all the more wrenching when Mary starts to lose it — panicking as she fears the worst possible outcome, her anticipation of defeat crushing.

The script gets a bit schematic by giving both Kevin and Mary 15-year-old sons to fret about while they remain occupied with their younger charges. However, the most intrusive element is Kevin’s personal crisis as he contemplates failing his son the same way he failed his father, sparked by a finger-pointing call from his ex-wife before all communication goes out. McConaughey is solid as the reluctant hero, but the belabored material does him no favors and ultimately feels like padding.

No matter. The claustrophobic action inside the bus is played with urgency and heart, engulfed in the darkness of smoke and the red glow of the encroaching fire. Kevin and Mary contend with backed-up traffic as evacuees flood the roads; people on foot waving guns; engine trouble; and mounting worries as the traumatized kids freak out, getting overheated and underhydrated. As different routes are revealed to be blocked or ablaze, Kevin becomes increasingly desperate, building to what could be a fatal decision as he plows through a path bordered by unpredictable fire.

There’s highly capable support in the cast from the unfailingly superb Vázquez, emanating gravitas, humanity and barely contained anger at the increasing frequency and spread of wildfires and the foolish refusal of those in power to address the growing threat. And Atkinson (fan favorite and queer icon Mrs. Fish on The Gilded Age) threads the needle between tough-cookie boss and salt-of-the-earth community member, especially in the genuinely moving closing scenes.

The film’s true star is the fire, and even if its personal drama can get in the way, The Lost Bus is a scary wake-up call. Bringing his characteristic flair for ramping up tension with handheld cameras and rapid cutting, Greengrass illustrates how easily the combination of lax safety standards and fire-friendly weather can build in what seems like a heartbeat into a mass-casualty event.