The Eaton and Palisades Fires that struck Southern California are believed responsible for about 30 deaths, according to news reports. The fires destroyed thousands of homes and caused hundreds of thousands of people to be evacuated.
Broadcast infrastructure seemed at risk; the fiery scenes captured during the Eaton Fire by cameras atop Mount Wilson in January quickly went viral. But although a building used for paging equipment succumbed to the flames, Los Angeles FM and TV stations that call the 5,700-foot summit home stayed on the air throughout, sometimes running on generator power during planned power shutoffs.
Nineteen FM stations maintain primary facilities atop Mount Wilson, according to data from the RadioLand app, while 26 TV stations transmit from Wilson, according to RabbitEars.Info.
What went right for the broadcast engineers involved? And what hazards should operators consider as they weigh risks from future fires? We asked three of them.
Calm in the crosshairs
Dennis Doty, RF engineer for NBC Los Angeles, was stationed at KNBC(TV)’s transmitter site on the east side of Mount Wilson on Jan. 9 when images of flames reaching the summit began circulating on social media.
NBC management called and told him he had to get out. “Everything’s fine,” he assured them. He stayed on the mountain throughout the fires, confident that despite surreal scenes nearby, the broadcast facilities themselves would stay safe.
During the emergency he ended up speaking live on air on KNBC and sister station KVEA(TV). He sounded calm in those broadcasts, but his mind was churning.
“My focus was split because I had to monitor 30 cameras to make sure I didn’t have a fire I needed to address,” he explained.
Doty is no stranger to fires on Wilson. He has weathered the Station Fire of 2009, the Bobcat Fire of 2020 and others. He has stayed up on the mountain for as many as 19 consecutive days, and in January he was there for at least 10.
Experience trained him to monitor the prevailing wind steering the Eaton Fire. “Eaton Canyon goes from Pasadena all the way up Wilson,” he said, noting that the area is popular for hiking. When the fire started, winds were blowing nearly 60 miles per hour in the opposite direction — southwest — so it was initially of little concern to Mount Wilson.
But then the winds died down, allowing the fire to make a beeline. “Fire likes to go uphill, and we’re kind of at the top of the chimney,” Doty said.
There were a handful of fire crews stationed atop the mountain, but most resources were committed to Pacific Palisades and Altadena. Doty felt that firefighting efforts at Mount Wilson were more reactive than proactive, with only about 12 trucks on hand.
Despite limited resources, Doty remained calm. The KNBC transmitter facility is built with concrete and has shelter areas. The nearby Wilson Observatory Dome also has basements.
“And we showed we could protect the mountain,” he said. Fire didn’t jump over to the other side of Mount Wilson Road, which he said was a tribute to good brush clearance. Yet the media images did not exaggerate the fire’s proximity. Flames came within about 15 feet, or the width of the road, of NBC’s transmitter property, and some of those flames were almost 60 feet in length.
KNBC’s fire safety plan includes adequate “defensible space,” defined by the California Department of Forestry and Fire Protection as a buffer between a structure and the surrounding area that helps slow or halt the progress of fire.
For example the station’s Mount Wilson site is surrounded by a metal shell.
“Good housekeeping outside is almost as important as inside,” Doty said. Its plan also includes mapping survivable egress routes and access to personal protective equipment, such as Doty’s fire tent.
“But I want to stress: If you don’t have good shelters in place, don’t do what I did,” staying atop the mountain.
The number one rule in a situation like this, Doty said, is to “never bring a victim to an emergency.” If you are not trained or lack supplies, stay out of the way.
Backups with backups
Doug Irwin, iHeartMedia’s regional engineering lead for the Los Angeles region, talked about the importance of having redundant systems in place.
He said iHeartMedia’s four FMs at Wilson — 92.3 KRRL(FM), 102.7 KIIS(FM), 103.5 KOST(FM) and 104.3 KBIG(FM) — have two auxiliary sites. Each site has backup power and STL links, but neither was needed during the January fire.
[Related: “Dealing With Repack — Moving an FM Cluster to a Temporary Site”]
The first, Deer Park, is an 800-foot tower less than a mile west of the main antenna group on Wilson. It provides full redundancy, which includes HD Radio, but given its proximity, it doesn’t offer full fire protection.
“It’s important that both of your sites don’t go out at the same time,” Irwin said.
He referenced similar challenges in the Riverside–San Bernardino market, where the Heaps Peak site and its auxiliary, 15 miles south, have both burned over in the last 20 years.
iHeartMedia maintains a second backup site for its L.A. stations, approximately 20 miles west in the Hollywood Hills, designed with fire and landslide resilience in mind.
Irwin emphasizes that having backup sites isn’t just about fires. “This includes tower maintenance. You really have to ask yourself: How badly do we want to stay on the air?”
Irwin added that the lack of wind turned out to a blessing, reducing the potential for embers to blow, which happened in Altadena.
Ron Thompson is chief engineer at University of Southern California’s 91.5 KUSC(FM). He can testify about the importance of backups after the station’s primary site on Mount Harvard, about a mile south of Wilson, took a hit.
Com Plus
A section of transmission line failed when Teflon inside the coax melted, which caused detuning.
(Read “How the Eaton Fire is Affecting KUSC Reception,” published by the station in January.)
“The burning vegetation below where the line path transitions from underground to open-air cable tray created an oven-like situation, especially under the steel plates,” Thompson said.
KUSC switched to its auxiliary site on Lookout Mountain in the Hollywood Hills. Though coverage was diminished, another broadcaster stepped in with a more advantageous setup temporarily. Full power was restored at Harvard later in February after repairs were made by the Frazier Park-based integrator Com Plus.
Fuel issues
Extended power shutoffs by Southern California Edison complicated operations. Irwin said the iHeart stations had to operate on generator power for two weeks, except for a 36-hour stretch when power briefly was restored.
At one point, iHeart provided 270 gallons of fuel to a generator owned by American Tower to keep three of its four FMs online. A supplier was able to deliver fuel daily.
“You have to have a ready source of fuel,” Irwin said, in case of fire or any other unexpected interruption to operations.
[Related: “Mt. Wilson Stations Rely on Generators”]
Doty said NBC consumed about 2,000 gallons per day. The network also maintains a contingency for helicopter fuel drops — around 500 gallons — with enough capacity to last nine days.
Irwin said he found the power shutoffs frustrating in part due to a lack of good communication from the utility during the emergency. He said this was a contrast with years past, when SCE even sent reps to SBE Chapter 47 meetings. The L.A. Department of Water and Power handles service at several of iHeart’s other sites, including the Hollywood Hills.
Irwin urged broadcasters to establish good communication with utility sources in advance so you know where to turn in an emergency. “You need to have a lead contact at your local power company,” Irwin said.
Also have a plan for how to exit the area if necessary. “If you go flying down the mountain, there’s a chance there’s going to be an accident or you’ll end up blocking the road,” Doty said.
In 2009, two firefighters died trying to retrieve gear. Doty watches for fire crew activity to inform his own egress decisions.
“If they’re going out or hunkering down, stay with them, but keep that communication going,” he said. NBC has simulated worst-case scenarios, including helicopter evacuation.
Who controls what
Jurisdictional considerations may come into play. Some of Mount Wilson is private land regulated by L.A. County while other parts fall under U.S. Forest Service.
NBC owns its Wilson transmitter site. Most FM broadcasters cluster in the “post office area,” surrounded by roads and managed largely by American Tower. Many lease land that is governed by the Forest Service.
Ron Thompson/KUSC
Such differences can complicate decisions, Irwin said, such as cutting a tree that blocks a microwave path.
NBC conducts annual brush clearance, hiring a crew for a week. Trees are trimmed to lift the canopy eight to 10 feet. Brush is removed but some vegetation is left to retain moisture and soil stability.
“Clear too much and the soil becomes hydrophobic,” Doty said. “Our idea is to let it flash through low and avoid canopy fires.”
Among tower maintenance and site management companies, Doty said, fire abatement can be “out of sight, out of mind, until it’s a problem.” Site managers also may be hesitant to disturb the natural landscape around towers.
[Related: “Inside Cumulus’ Strategy for Emergencies in Oxnard-Ventura-Santa Barbara”]
Doty said a tall tower on the west side of Wilson sustained damage in January likely due to poor brush clearance.
“You can’t ignore these important sites in big markets,” he said. “These tenants are paying thousands, and for someone not to even come up and take out the trash or clean the toilet in five years — that’s a problem.”
Irwin said iHeart’s relationship with American Tower is strong, which is especially important because the tower management company maintains the generator that supports three of iHeart’s L.A. FMs.
Thompson of KUSC emphasized the value of partnerships. To replace its damaged transmission line, the station relied on a mover familiar with its logistical needs to handle last-mile delivery of a massive coax spool.
“Without that prior relationship, we would’ve had an extra challenge,” he said.
Many nines
In his 18 years with NBC, Doty says the total unplanned downtime across both stations he manages has been less than an hour.
“Making sure the site is prepared for a fire — that it can survive a fire — that’s probably one of the top two priorities I have,” Doty said.
iHeart’s Irwin echoed the sentiments.
“It’s never going to hit 100 percent uptime,” Irwin said. “But we’re going to push as many nines into 99 percent as we can. No excuses.”
Thompson added that a collaborative email list for Mount Wilson engineers was helpful during the fire for sharing weather updates, road conditions and scheduling repairs.
Doty said the biggest lesson from the past two decades is simple: Keep your site defensible.
“Be a good steward of your area and your properties,” he said.
And have a plan before the fire ever gets close.
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