Eastern portion of Santa Paula Ridge near the Ventura County town of Fillmore, where Cal Fire engineer Cory Iverson was killed. (Cal Fire)
Cory Iverson, the Cal Fire engineer killed during the historic Thomas Fire in Ventura County last month, died after a rapidly spreading fire cut off his escape route, forcing him to run for his life through head-high vegetation before becoming trapped in a dead-end gulch.
Cal Fire's preliminary report on the Dec. 14 incident says vegetation in the area was so thick that personnel nearby and watching from helicopters overhead could barely see Iverson as he ran down a hill, fell, got back up and was finally overtaken by the fire.
The Cal Fire Green Sheet says that as Iverson fled, "in some cases, all that could be seen was the top of his helmet."
Iverson, 32, was a fire apparatus engineer who worked in Cal Fire's San Diego unit. He was the only firefighter killed fighting the Thomas Fire.
Cal Fire Details Desperate Moments Before Firefighter's Death in Ventura County Blaze
The Thomas Fire burned 281,893 acres -- about 440 square miles, or nine times the area of San Francisco -- and is listed as the largest blaze in the state's history. The conflagration blew up in the wake of unrelenting high winds that lasted nearly the entire first half of December and prompted a record 13 days of continuous red-flag warnings from the National Weather Service.
The Cal Fire Green Sheet notes that one measure of the combustibility of fuels, the energy release component, was at a 10-year high the day of Iverson's death.
Iverson was part of a strike team assigned to work the edge of a containment line on a ridge north of the town of Fillmore -- a job that began Dec. 13 and continued into the following morning.
At around 3:30 a.m. Dec. 14, the report said, wind gusts began to pick up.
"That's the time of day when there's supposed to be the most humidity, things are supposed to be the quietest," Cal Fire
Deputy Chief Scott McLean said Tuesday. "But as you can tell by this report ... activity started picking up, the winds started changing."
Just before 7 a.m., the fire intensified and began moving down a height known as Santa Paula Ridge toward Fillmore. The blaze was moving fast enough that firefighters found it impossible to start building a fire line by hand, so two bulldozers were called in to dig containment lines.
When the dozers were finished, about 9 a.m., Iverson and his four-member team went to work laying hoses to defend the new line. Iverson told the crew its safety zone would be "into the black" -- an area that had already burned.
At that point, however, spot fires began appearing in "the green" -- unburned vegetation on the downhill side of the containment line. Iverson tried to contain that flare-up with a scraping tool he was carrying. Almost immediately, another spot fire erupted, another 20 feet into the green.
"All of the sudden, another spot fire," McLean said. "That shows you how the fuel is so receptive to fire in December. Every ember that went across, I'll guarantee you, started another fire."
As Iverson started battling the second spot fire, at about 9:25 a.m., it erupted, the Green Sheet says. More spot fires ignited and spread rapidly, and attempts by the nearby firefighters to douse them didn't work.
The fire now blocked Iverson's path back to the line and safety in "the black." In an attempt to escape, he headed downhill and requested immediate air support over the tactical channel.
Two helicopters attempted to dump water on the flames to create an escape route for Iverson, again to no effect. More spot fires blew up in front of Iverson as he ran, forcing him to change course toward the nearby gulch -- a deep ravine.
He was seen falling, getting back up, and eventually ending up in the gulch. A half-dozen helicopters dropped fire retardant and water in the area where he was last seen, but it was too late. Firefighters venturing into the gulch found Iverson dead just before 10 a.m.