Prescribed burn erupts into 10,000-acre blaze in Southern California

PHOTO MIKE MEADOWS A California Division of Forestry firefighter uses a drip torch to ignite a backfire along State Route 241 to keep the flames from jumping the highway on Feb. 7 in Orange County, Calif.

On Monday, Feb. 6, a large wildfire erupted at Sierra Peak in the Cleveland National Forest (CNF) near the border of Orange and Riverside counties in Southern California. The Sierra Fire ultimately burned more than 10,000 acres, forced the evacuation of approximately 2,000 homes and left eight firefighters with minor injuries.

Unexpected Winds Spark Fire
Capt. Stephen Miller, a spokesperson for the Orange County Fire Authority, says the likely cause of the fire was the rekindling of a U.S. Forest Service (USFS) prescribed burn conducted four days earlier. "They believe an underground root was smoldering and went undetected during inspections," he says. "There was no indication of a Santa Ana wind; otherwise, they wouldn't have had the burn. But the wind kicked up, probably uncovering the root, and embers started sparking out from that." Upon firefighters' arrival, the fire was only five to 10 acres in size, but moving through heavy brush at a rapid rate of speed. According to the Los Angeles Times, the prescribed burn was part of a USFS project to clear more than 1,000 acres of brush by May 26. Joan Wynn, public affairs officer for the CNF, says a review of the fire's cause is currently underway.

The unified command for the Sierra Fire consisted of the USFS, the California Department of Forestry and Fire Protection (CDF) and the Orange County Fire Authority, as well as the Anaheim and Orange fire departments, due to the threat to the communities in this area. Irvine Regional Park in Orange was the site of the command center and a staging area.

Fire officials first ordered the evacuation of 665 homes in Anaheim Hills and 500 in Orange. An additional 900 homes in Anaheim Hills were advised to voluntarily evacuate. "I have to applaud the homeowners and those affected by the closure," Miller says. "They listened to us and allowed us to do what we needed to do." While the fire was not an immediate threat to the homes, fire officials made the orders as a precaution. Additionally, fire officials ordered the closure of State Route 241, a major connector between Riverside and Orange counties, so fire apparatus could have access to the road.

AP PHOTO/THE REGISTER, MARK AVERY Firefighters conduct a burnout along the northern edge of State Route 241 to deprive fuel to a brush fire burning in the Cleveland National Forest.

A Crucial First Few Days
High winds, hot temperatures and rough terrain hampered firefighting efforts. The fire burned through chamise and across steep hills covered with highly flammable chaparral, making it difficult for firefighters to access the fire. Additionally, the Santa Ana winds that likely helped rekindle the prescribed burn continued to fan the flames.

Officials feared the fire would jump State Route 241 and threaten residential communities in the area. Miller says the fire spotted twice on the opposite side of 241 in the first 24 hours, but firefighters quickly knocked down those blazes. With things looking up, fire officials lifted the evacuation order on Feb. 7. "My huge buzz words were ‘cautiously optimistic,'" Miller says. "On the second day, when we released the homeowners back to their homes, we started feeling more comfortable with how everything was going."

Firefighters spent the night of Feb. 7 setting small backfires to halt the progression of the fire. By the next day, the fire had eaten through approximately 6,500 acres. However, diminished Santa Ana winds aided firefighting efforts. With the fire about 40 percent contained, fire officials reopened State Route 241.

At the height of firefighting efforts, 2,192 firefighters from 165 engine companies battled the fire, as well as six fixed-wing aircraft and five helicopters, Miller says.

On the morning of Feb. 10, fire officials reported that the number of acres burned remained the same overnight for the first time since the fire started. Officials began reducing the number of firefighters on scene. Specifically, with 62 percent of the fire contained, 745 firefighters left the scene. The remaining firefighters continued constructing fireline and clearing brush to deprive the fire of new fuel.

Working Together
Firefighters achieved 100 percent containment on Feb. 12 and control on Feb. 22. As of Feb. 28, Wynn says, USFS crews were still monitoring and patrolling the area.

Miller adds that the unified command was a bit large for this type of fire, but it was great to see everyone working together so well. "It was really morale boosting to see all the patches drop off the uniforms so we could come together and get the job done," he says. "For a large incident, it went very smoothly."

The Sierra Fire ultimately burned 10,854 acres, and no structures burned. Miller says the estimated cost just exceeds $7 million.