A five-alarm vegetation fire engulfed portions of Sign Hill in South San Francisco just after noon on Friday and was contained within about two hours.
Just three hours later, a four-alarm fire broke out in the light industrial area south of downtown.
South San Francisco police said two juveniles spotted by an alert resident leaving the scene right after the fire started were identified and questioned. The two, aged 14 and 16, admitted to being responsible for starting the fire. They were released to family pending the completion of the investigation, police said.
The Sign Hill fire threatened homes and mandatory evacuations were ordered, but no homes were ultimately destroyed and no one was injured, however, there was minor structural damage, fire officials said. It is not yet known how many acres burned or what caused the fire.
Mandatory evacuations were issued for Carnelian Road, Sonja Road, Mountain Road, Ridgeview Court and Viewmont Terrance and remained in effect as of 3:30 p.m., as crews performed mop up work and continued to extinguish spot fires. A temporary evacuation center was established at the MSB Social Hall located at 33 Arroyo Drive.
Flames burned through the vegetation, including especially flammable eucalyptus trees, to the left of the “South San Francisco The Industrial City” sign and the billowing smoke could be seen from miles away. Winds carried the smoke southwest over Pacifica, briefly turning the skies red there.
More than 25 fire engines along with helicopters and fixed-wing aircraft responded to the fire. At its height, nearby residents lined the sidewalks watching nervously as fire crews worked to contain the blazes, and several of them could be seen hosing down their homes.
City officials in the spring and for the first time in years cleared vegetation and established fire breaks on Sign Hill, which helped contain the fire, said Heather Enders, spokeswoman for the South San Francisco Fire Department.
“We really worked to prepare ahead of time to ensure lives and homes are protected,” she said. “We knew this was coming.”
Enders noted the weather on Friday that reached 90 degrees with low humidity and dry winds was especially ripe for a fire. A red flag warning was in effect throughout the Bay Area that day.
Not long after the Sign Hill fire was contained, another four-alarm structure fire broke out on Starlite Street and was contained shortly thereafter. Larch Avenue between Kearny Street and Lincoln Street was evacuated, police said.
The South San Francisco fires came less than one month after a four-alarm vegetation fire erupted in Belmont, prompting evacuations of about 40 households. That fire was also contained within hours with no injuries and no homes destroyed.