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WILDFIRE lessons:                          1991 Oakland-Berkeley Hills Fire



Driven by unrelenting winds, in just three days — Sunday, Monday, Tuesday; October 20, 21 and 22 of 1991 — the fire became the most destructive “Wildland-Urban Interface” (W.U.I.) fire in California's history up until then, with an estimated $1.5 billion in damage in 1991 dollars; over $3.5 billion in today's dollars.

The devastating "Hills Fire," aka, the "Oakland hills firestorm", and "The Tunnel Fire" by CalFire, spurred the creation of the Hills Conservation Network by a group of residents — among them several whose homes were destroyed in the fire, and one whose aged mother was trapped by and killed in the fire.  They were impassioned and determined to cut through the usual politics and bureaucracy, get an accurate, honest and transparent analysis, and publicize the truth of the fire’s origin and causes.  Only then could the necessary changes be made to prevent another future disastrous fire for future generations. 

SEVERAL OFFICIAL REPORTS on the 1991 Hills fire were commissioned and released in 1992, including the Berkeley & Oakland Mayor’s Task Force, one by FEMA (The Federal Emergency Management Agency of the federal government), and a one by the former Chief of Fire Prevention of the Oakland Army Base, David Maloney.  Two more reports are also referenced later on this site: one by the U.S. Forest Service in September, 2018, and another by Fire Science Lab researcher Jack Cohen.




































In the aftermath of the Hills Fire, the Hills Conservation founding members lobbied long and hard for critical improvements for neighborhood fire safety, including:  Today, fire hydrants are universally accessible.  Water pumps have been undergrounded, making them impervious to wildfires.   Many houses which had made few or none of the simple, recommended preparations to deter home igntion, like removing flammable, dry vegetation from roofs, gutters and near houses, have now done so.  "Defensible space" is now routinely advised by fire agencies, and even mandated by municipalities.


READ NBC News detailed report of the fire:


However, in the years and decades since 1991, some “native” plant advocates distorted the truth or even lied about the Hills fire to blame and target specific species of trees; trees they have for years wanted to cut down for purely aesthetic reasons — by the tens of thousands.  They realized they could advance this agenda by exploiting heightened fear of future wildfires.


Not content to simply plant trees and plants they prefer, some native plant advocates advise cutting down thousands of healthy trees, claiming they pose a unique fire danger, despite no scientific literature supporting this claim.  Trees and even entire forests covering acres are treated like weeds in a garden.  The term "weed" is itself a term without botanical definition.  It means simply a plant one does not want in the garden.  But in the Oakland and Berkeley forests, this “weeding” of trees is done on a colossal scale with chainsaws and bulldozers clearing hillsides of healthy forests over 100 years old.  As a result, hillsides are destabilized, ecosystems are destroyed, windbreaks and fog-capturing stands of tree that mitigate wind-driven fires are destroyed, along with precious wildlife habit.


This miguided ecological damage is then compounded: toxic herbicides are regularly applied to unwanted plants and stumps of cut trees to prevent their regrowth.  In the three decades since the Hills Fire, extensive deforestation has been done in the name of “fire danger mitigation” and "habitat restoration."  Deforestation is neither.  Cutting down forests is the opposite, both INCREASING wildfire danger  and destroying wild habitats.  Forests in the East Bay Hills , like forests everywhere, dramatically increase the moisture of area in myriad ways.  READ "Trees & forests VS. chaparral & grasslands.


In recent years, HCN has been successful in educating the public and discouraging agencies, institutions and municipalities from advancing policies that target trees by species under the guise of fire danger mitigation. 

Monterey pine, acacia and eucalyptus trees have been erroneously blamed for the size or ferocity of the 1991 Hills fire, despite these trees having no more significant role in the fire than other trees species.  (As detailed in the reports referenced above.)  A far greater contributor to the resultant firestorm was the quick ignition and higher combustion temperatures of houses themselves.  They were highly flammable with their dry lumber, paints, solvents, gas lines, etc., and burn hotter than any species of living, water-filled trees.


Healthy trees of all species, regardless of their country of origin, rather than being fire hazards, reduce the overall temperature of a landscape, dramatically increase its moisture conten, generate fog and significant annual fog drip rainfall.  


Perhaps most important, trees of all species are invaluable for their ability to sequester carbon in our current era of anthropogenic climate change.  A warming climate is what is creating our longer, hotter, drier summer-autumn fire seasons.  And as always, tree provide numerous other essential ecological services, including stabilizing steep East Bay (and Bay Area) hillsides and being wildlife habitat.  In fact, so-called "native" chapparal like coyote brush (Baccharis pilularis), is more easily ignited in a wildfire than trees.   READ MORE about chaparral and forests in comparison.


Both trees and chaparral are in fact pyrophytic, meaning they have evolved to not only survive fire, but propogate with it, and provide numerous benefits to the ecosystem they are an integral part of.  Fire itself, as more fire ecologists and biologists have been writing and speaking about in recent years, provides the essential ecological function of renewing forests.  Our challenge is to apply simple methods to make our homes and structures in and near forests igntion-resistant, not cut forests down.  READ MORE.


If you’ve ever heard eucalyptus trees described as “flammable,” “hazardous,” or “dangerous,” this, too, is a claim without scientific basis. It's a chilling example of how a lie repeated often enough, by people with an entirely different agenda than wildfire mitigation, can become perceived as truth by an unsuspecting public and an underformed media.


In fact, California bay laurel trees contain more “volatile” (aka “essential”) oils than do eucalyptus trees.  Bay trees also grow closer to the ground so they can be more easily be ignited than taller, stout-trunked eucalyptus trees by grass and chaparral fires common in the hills.  So bay trees could be labeled more “flammable” than eucalyptus or some other tree species, but this misses the larger point that all living trees are more resistant to ignition in a wildfire than grasses and smaller plants without thick, fire-resistant trunks.


Pine and eucalyptus, like redwood, bay and oak trees, all burned in the Hills fire. They all generated firebrands — as did houses and other structures that burned.  Human judgment, including by homeowners, and poor fire preparedness planning were more responsible for the fire’s catastrophic result than trees were.  All this is detailed in the official reports on the 1991 Hills fire, referenced on this page and available for interested readers, here:


READ THESE CRITICAL REPORTS about the 1991 Hills Fire, also valuable resources for general wildfire and vegetation information:

• 1991 FEMA (Federal Emergency Mangement Agency) Report: CLICK HERE

• 1992 Oakland-Berkeley Mayor’s Report: CLICK HERE

• 2009 Maloney Report CLICK HERE

Fire Science Lab report, "The Wildland Interface Fire Problem," by Jack Cohen: CLICK HERE

25 PEOPLE KILLED.  125 PEOPLE INJURED.  OVER 3,500 HOUSES, 450 APARTMENTS DESTROYED.  To those who witnessed the 1991 Oakland-Berkeley Hills Fire or its aftermath, its memory induced fear of future wildfires in the East Bay hills.  And spurred decisive actions to prevent them.

• How the fire began: on Saturday, October 19, 1991, as a grass and brush fire in the Berkeley hills northeast of CA routes 24 and 13.  It was extinguished by firefighters who then left the area by nightfall.  The next morning, Sunday, October 20, 1991, (“Diablo”) winds from the east kicked up embers below the crust of charred and dampened grasses during the firefighter’s mopping up operations—and these embers re-ignited the fire.  Fanned by the steady winds, the flames quickly spread, to more seasonally dry, autumn grasses, brush, and trees and houses;

• Trees per se, including eucalyptus and pine trees species, were NOT of particular significance in fueling the blaze;

• Houses burns hotter than trees of all species, and create greater volumes of embers ("firebrands," in fire science terminology) and burning airborne debris.  The showers of firebrands ignited other houses with combustible (e.g., shake) roofs and gutters filled with pine needles and other fine fuels.  Linnea Edmeier, a retired firefighter for CALFIRE, the wildland firefighting agency, produced a documentary, “Burn,” about the 1991 fire while pursuing her master’s degree in journalism at UC Berkeley.  Edmeier said, “Homes are fuel.  When the homes are so close together and they are covered in brush, they are going to burn.”

• The fire became a firestorm, meaning it generates its own heat-driven winds and weather that perpetuates the fire;

• Many factors contributed to the fire's severity and the inability to contain it, including:
1)  the East Bay hills’ steep, narrow roads with many cars blocking fire truck access;
2)  a shortage of water, and hydrants lacking universal hookups, other district’s trucks couldn't access all hydrants;

3)  some above-ground water-pumping facilities were destroyed in the fire;

4)  too many houses with highly flammable materials;

5)  accumulation of "fine fuels" debris on many houses' roofs meant hundreds of firebrand ignitions.

Despite huge and courageous efforts by hundreds of firefighters, inadequate planning

  and infrastructure for a fire of this ferocity contributed to the catastrophic result.  

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