WEST HILLS, Calif.—Her gray SUV packed and a fire-proof bag ready, Melissa Bumstead didn’t waste any time Monday as plumes of smoke engulfed the sky near her suburb.

Most neighbors in West Hills—about 30 miles west of downtown Los Angeles—stayed put after only a voluntary “evacuation warning” was issued for the area. But not her. 

As the ever-growing Sandy Fire swept across Southern California, the 45-year-old mother could only think of one thing. 
Bumstead lives less than four miles from the site of possibly the worst nuclear meltdown in U.S. history besides the Three Mile Island accident.

The Santa Susana Field Laboratory, or SSFL, is known locally as a problem site—with a pockmarked history amid a spotty cleanup. A blaze hitting the former nuclear reactor and rocket testing site, Bumstead is sure, would be a cataclysm. 

“This is what it looks like to evacuate when you’re scared,” she said Monday, “because if the smoke were to be radioactive or toxic, you don’t want to breathe it.”

Bumstead returned home Tuesday but remains on alert as the Sandy Fire rages on. 

The fireline was about a quarter-mile from the site on Tuesday morning. Boeing—which has owned SSFL since 1996—said it has evacuated all personnel from the site who are not involved with fire control.

“We are actively monitoring the Sandy Fire near the Santa Susana site and are in close coordination with local authorities and emergency responders,” a Boeing spokesman told Inside Climate News in an email. 

“This is an ongoing situation, and as it evolves, we will continue to monitor fire conditions,” he said, deferring to the state for other questions.

Radiation exposure has short-term as well as long-term impacts, including greater risk of developing cancer and possible harms to cardiovascular and immune systems.

The Sandy Fire, which surpassed 1,300 acres on Tuesday with only 5 percent containment based on early response efforts, burned near Simi Valley. 

More than 33,000 people in the valley and other communities were placed under evacuation orders. At least one home has been destroyed as of Tuesday afternoon. The cause remains under investigation. 

Fire crews made strides in cutting firelines since Monday morning, when the incident first began as a brush fire. At about 4 p.m. Pacific on Tuesday, prevailing winds shifted direction from the west, fueled by out-of-season Santa Ana winds. 

The shifting conditions placed the Santa Susana Field Lab in the immediate path of the Sandy Fire—raising alarms from nearby families like Bumstead’s. 

Fire crews raced to the scene. 

“That is an area that we’re trying to keep the fire out of and we’re putting multiple dozer lines in place, as well as our hand crews are working to increase containment and build contingency lines,” Andy VanSciver, a firefighter and spokesman for the Ventura County Fire Department, told Inside Climate News on Tuesday.

VanSciver said first responders were at the former nuclear site “right away.”

The state Department of Toxic Substances Control did not immediately provide comment Tuesday afternoon. 

The U.S. Department of Energy said in a statement online that it “is closely monitoring the Sandy Fire located adjacent to the Santa Susana Field Laboratory.” So far, “there is no impact to the site,” the agency wrote.

VanSciver said he was confident the community would be protected as the fire department arrived at the site quickly, but noted that updates will be provided online.

Not the First Wildfire Threat

Peter Hemken paused Monday night on his walk up the steep Sequoia Avenue in Simi Valley, overlooking a ridge covered in gray smoke. 

What began as a small cluster of fires from his sight line became a full out strip.

“Oh my God, that’s really flaring up,” the 73-year-old remarked, pulling out his phone for a photo.

Every hour or so since Monday morning, Hemken joined others in walking up the hill to see the Sandy Fire’s progress.

“I used to work in engineering up at Rocketdyne,” he said of the nearby facility that developed space shuttles. 

A Simi Valley resident for over two decades, Hemken was well aware of the Santa Susana Field Lab. Residents of his Simi Valley neighborhood have not had to evacuate because of a wildfire in recent years, but they are always ready to. The lab has something to do with it.

“I would hate to see a fire get up there,” he said, pointing toward the SSFL site. “There’s still a lot of nasty chemicals up there.” 

The SSFL cleanup plan is still being finalized, having been expanded, and then stalled, several times in the last 20 years. Through interim measures, approximately 6,000 cubic yards of the most contaminated soil was removed in 2024, the year excavation began and the only one with data available. But that cleanup was limited to a single area. The scope of the full remediation is still being decided by the state, federal authorities and Boeing. 

The Sandy Fire on Tuesday encroached uncomfortably close to the former nuclear site’s north buffer zone, according to residents and a perimeter map of the area’s burn zone.

Melissa Bumstead said health concerns surrounding the site are personal to her. Her daughter, Grace, has had two bouts of a rare form of leukemia, which the family believes is linked to the radiation from SSFL.

She began campaigning 12 years ago for a complete remediation of the former nuclear test site soon after her daughter’s cancer diagnosis. 

“It was considered an urban legend,” Bumstead said of cancer links to the site. “It wasn’t until [my daughter] got diagnosed that we started doing research and found out … there were a bunch of studies by the University of California, Los Angeles, and epidemiological federally funded studies.” 

As it turned out, “the research was there. It just wasn’t being communicated,” she said.

One of the reports that pushed Bumstead toward founding her advocacy organization, Parents Against Santa Susana Field Lab, was a 2007 study led by Hal Morgenstern for the Agency for Toxic Substances and Disease Registry and the Centers for Disease Control and Prevention.

Morgenstern, an epidemiologist at the University of Michigan, found residents within two miles of SSFL face a 60 percent higher rate of certain cancer diagnoses than those living five miles away. 

That study—though not enough to label SSFL as the cause of the higher cancer rate—shed light on the strong correlation between proximity to the site and cancers triggered by radiation exposure. 

That’s why residents worry whenever air quality alerts start to ping on their phones and a wildfire approaches.

It happened in 2018.

The Woolsey Fire burned through 80 percent of the SSFL site, though most of the affected area was in the southern buffer zone and in the rocket testing area, not the nuclear testing area. 

Initially, the state Department of Toxic Substances Control assured the community that there was no risk of radioactive contamination, an assertion that the agency seemingly confirmed in the 2020 Final Report on the Woolsey Fire. 

However, an independent study looking at 360 samples from the area surrounding the burn zone found that 3 percent contained radioactive particles that could be traced to the SSFL. The study, conducted by a doctoral student at Worcester Polytechnic Institute and the co-founders of nuclear watchdog group Fairewinds Energy Education, analyzed more than 10 times the samples taken by the state for monitoring. 

Boeing had no immediate comment when the study was released in 2021, issuing a statement to NBC4 in Los Angeles that said: “Cleanup at Santa Susana will continue to follow California law… The transformation of Boeing’s land at Santa Susana from a field laboratory to open space is well underway.”

In 2023, Boeing released the results of a study by Risk Assessment Corporation (RAC) that it funded. “Based on the soil sampling, we found no evidence of SSFL impact in off-site soils as a result of the Woolsey fire,” the study says. “Moreover, we found no radionuclide impact on the off-site soils we sampled from past operations of the SSFL”

Parents Against the Santa Susana Field Laboratory responded on its website: “Boeing redid the Woolsey Fire study…collecting samples nine months after the fire. We collected our samples within a month. Our study was peer-reviewed by independent scientists. Boeing’s scientists were paid by Boeing and their findings were NOT peer-reviewed.”

Bumstead received training and volunteered to collect samples for the independent study, along with the co-director of Parents Against SSFL, Jeni Knack. 

Bumstead was glad to be able to be a part of that research and hopes their findings of scattered radioactive material up to nine miles away from the lab will add pressure for better monitoring this time. 

“We have such a deeply ingrained belief that if it wasn’t safe, the government wouldn’t let us live here,” she said of local residents. After her experience with the Woolsey fire, she said, she knows that is not always the case.

Although the Sandy Fire has not reached the grounds of the SSFL as of now, it has burned “concerningly” close to the site of the 1959 sodium reactor meltdown, according to one former firefighter with CAL FIRE who asked that his name not be used. 

He recommended residents seal off living areas and create positive pressure in their homes by turning on fans and using air filters. The radiation is contained in dust and ash particles, he said, so the sooner you wipe everything down and wash them away, the lower your risks of exposure. 

People in Simi Valley said they are taking such measures but thinking of the long term, too. As wildfires grow fiercer due to man-made climate change, infringing on more homes and more people, Bumstead fears what ferocious winds and massive blazes could do.

“There’s a twisted joke that we have here that the Santa Susana Field Lab will be cleaned over time, because all of it will blow off into the surrounding communities,” said Bumstead. “The surrounding communities will be contaminated, but the site itself will be clean.”

For those concerned about the influence of Big Tech and billionaires on California’s future, Tom Steyer looks like an obvious choice. A billionaire who amassed his fortune after founding Farallon Capital Management, one of the world’s biggest hedge funds, Steyer quit the firm in 2012 and turned to philanthropy, political advocacy, and climate activism, among other pursuits. Now, he’s jostling for position among a handful of Democratic and GOP candidates looking to advance from a June primary and then win the California governorship this November.

Ahead of the midterms, I’m talking to candidates relevant to WIRED’s interests: A few weeks ago I spoke with Alex Bores, a candidate for New York’s 12th Congressional District, whose history as a Palantir employee and stance on AI regulation has attracted the ire of Silicon Valley–backed super PACs.

Steyer felt like the next obvious choice for a conversation: He’s running to lead a state where issues like AI, immigration enforcement, and climate change, among other core WIRED subjects, are paramount. Steyer’s posture in the race is also unique. He’s been described as a “class traitor” for ostensibly eschewing his fellow elites, voiced support for California’s controversial Billionaire Tax Act—which has everyone from Sergey Brin to Peter Thiel either making moves to or threatening to flee the state—and campaigned hard on affordability, climate policy, and the promise that he’s immune to corporate influence. (As a billionaire spending more than $130 million on his own gubernatorial campaign, I certainly hope he would be.)

As I said, for some Democratic voters, Tom Steyer seems to check a lot of boxes. Then he starts talking.

Steyer is adept, as politicians usually are, at toeing the line. But the line, in politics generally and California specifically, seems to be the problem: Steyer, or whomever is elected to the governorship this November, will be walking an exceedingly thin one. Taxing California’s billionaires without alienating them. Getting a grip on the state’s AI development without throttling it (or, again, alienating the billionaires building it).

I could feel Steyer’s reluctance to come down too firmly or dig in too deeply on issues, maybe to avoid alienating any potential voting block. Which made me wonder: Can Tom Steyer be a pro-billionaire governor who also taxes the hell out of them? Can he rave about the “mind-blowingly amazing” advances in AI while bringing the industry to heel? Can he learn the name of WIRED’s global editorial director (me) before she interviews him?

The third question is answered in the interview. The former two will be formidable challenges for anyone elected to California’s governorship—and I didn’t leave our conversation convinced that Steyer’s posture is a particularly coherent one. The minimum requirement for a California governor might be the ability to use Google.