LOMA PRIETA — More than 3,700 feet above San Jose, the rescue of this majestic peak — the home of critical Bay Area communications equipment — is a survival story in a tale filled with heartbreak.
The Loma Fire that ignited Monday has claimed 4,147 acres and eight homes and injured a firefighter, who was transported by ambulance to a hospital on Thursday night. Only 34 percent contained by Thursday night, the blaze still threatens 325 structures and is burning in steep, inaccessible canyons covered with drought-stressed fuel. And there are new worries that incoming weather — gusty winds from the northwest caused by an incoming low-pressure system — could push the fire across its southeastern perimeter along Casa Loma Road.
But atop Loma Prieta, “we stopped it here at one of the most critical infrastructure sites in the Bay Area,” said Jonathan Cox, a battalion chief at Cal Fire, walking through ankle-deep ash on the mountain’s peak, which offers views from Mount Diablo to Monterey Bay.
The inferno came within yards of repeaters and other communications equipment that relay signals from county emergency services such as 911, the U.S. Geological Survey and private providers like radio, television, AT&T, ham radios, taxi services, security alarm services and others.
The repeater towers on Loma Prieta are essential to sending messages across mountains, Cox explained. “This is the kingpin of communication systems — it repeats and relays what people say to each other when they can’t see each other. If a firefighter in Gilroy wants to talk to a firefighter in Santa Cruz, they’re not in line of sight. Their signal has to go through a system of repeating.”
As the fire roared closer and closer toward the peak, PG&E turned off power through the transmission lines that send electricity to the towers because they pose a threat to firefighters. An estimated 18 power poles have been so badly burned that they’ll need replacement, PG&E officials said.
Suddenly, backup emergency generators — filled with flammable propane and diesel fuel — automatically switched on to ensure continuous power.
These generators continue to keep the site going, supported by trucks delivering fuel to the 3,786-foot-high peak, said Annabelle Louie, incident commander at PG&E for the Loma Fire.
The blaze came perilously close to these 1,000-gallon tanks, which would have exploded like small bombs. But it was knocked down by fire retardant dropped by small aircraft, which flew like butterflies past tall and treacherous antennas and cables.
“We didn’t have time to get to release” the fuel, Cox said. “And we wouldn’t put firefighters in a direct path like this, where it was beyond a reasonable expectation of survival. It was really just a matter of slowing the fire’s impact to take the heat out of it when it hit.”
Loma Prieta is used by California’s Office of Emergency Services, ham radio operators and wireless phone companies, among others, said Laurel Anderson, spokeswoman for Santa Clara County. Adjacent Crystal Peak is used by AT&T, U.S. Geological Survey, ham radio operators, taxi companies, wireless servers and security alarm companies. And nearby Chual Mountain is the repeater location for the Santa Clara County’s Sheriff’s Department, fire department, Emergency Medical Services, parks department and all other county departments that have repeaters, Anderson said.
All three ridgetops had largely cleared of brush, so the fire’s progression slowed due to lack of fuel as it approached.
On Crystal Peak, the USGS for two days lost the major radio microwave relay to the Northern California Seismic Network, which records earthquake tremors as far south as San Luis Obispo. The signals were instead transmitted by a T1 landline up to Santa Rosa and then down to the USGS Menlo Park offices.
Just a few miles away on Mount Umunhum, the National Weather Service and owner Scott McQueen watched nervously.
“We all raced up there,” said McQueen, who owns the Mount Umunhum property with his sister and leases it out to government and private communication companies. “We opened gates and looked at equipment to make sure emergency generators had fuel.
“Then,” he said, “we just crossed our fingers.”
The National Weather Service shut down its radar for 12 hours. A technician with the weather service quickly drove up to its radar site on Monday afternoon, past road blocks, and flipped the switches to stop the radar from scanning the skies.
Weather service officials say they knew there were no dangerous storms headed our way — and feared that smoke and fire retardant could badly damage the delicate radar, air conditioning units and generators.
“We shut it down cold,” said Bob Benjamin, of the National Weather Service. “That radar is our little guardian in the sky, our primary means of evaluating an area when weather is coming.” If damaged, he said, “we could have been without radar for several months, waiting for parts and repair.”
But, he added, “everything went in our favor that night.”
