By Jeff Barnard

The Associated Press

GRANTS PASS, Ore. - The number of people killed fighting wildfires in the U.S. hit 24 last year - five of them a U.S. Forest Service engine crew overrun by flames as they tried to protect homes in Southern California.

The 2006 death toll is not an all-time high, but is part of a rising trend - double the number in 2005, and six more than the average of the past 10 years. The 10-year average has been rising, too, from 6.6 in the 1930s to 18 in the 2000s.

Experts warn that the size and intensity of wildfires is increasing due to longer, hotter and drier summers and a buildup of fuel from trying to put out every fire. As a result, wildland firefighters face greater dangers, particularly trying to protect the growing number of homes in the woods.

andquot;More telling than anything is where the fires are,andquot; said Dick Mangan, a retired U.S. Forest Service fire program leader at the agency's Technology and Development Center in Missoula, Mont., and author of a report on wildfire fatalities from 1990 to 2005.

andquot;Many of them are in the area known as the Wildland Urban Interface,andquot; the zone of rural homes outside towns in the West, Mangan said. andquot;The five guys who died on the Esperanza fire - if that had just been a pure Southern California brush field, those guys never would have been where they were. But there were homes to be protected up there.andquot;

Bill Gabberet, executive director of the International Association of Wildland Fire, noted research indicating climate change has made summers hotter and longer, drought has afflicted much of the West, and the old Forest Service policy of trying to put out every fire by 10 a.m. has created a buildup of fuels in forests.

Firefighters are increasingly being sent in close to fires -- what firefighters call direct attack or working with one foot in the black -- to protect houses in the woods, he said.

Mangan added that firefighters have the experience and research to justify keeping their distance from explosive fires, but when TV news shows air tankers on the ground and firefighters sitting on their engines while homes are burning, it creates andquot;tremendous pressureandquot; to attack a fire that would be left to burn if no homes where involved.

Within hours of the Esperanza fire starting Oct. 26 outside Two Pines, Calif. -- authorities have charged a man with murder for starting it -- 50 mph winds were driving flames up to 90 feet high through dense chaparral, overrunning the crew of San Bernardino National Forest Engine 57 as they tried to defend a house, according to a preliminary report by the California Department of Forestry and Fire Protection.

Results of a Forest Service investigation are not out yet.

andquot;We are fighting fires in the wildland urban interface more frequently because the wildland urban interface is growing,andquot; said Mark Rey, U.S. undersecretary of Agriculture in charge of forest policy. andquot;With 60 percent of new home construction nationwide being in the WUI, that's 8.4 million homes from 1990 to the present. You take a household size of four people, you've moved the equivalent of the population of California into the wildland urban interface in the last 15 years.

andquot;The good news,andquot; Rey added, is that only 800 homes were lost last year, despite a record 1 billion acres burned, compared to 3,000 homes lost in 2003, when 5 million acres burned.

Federal, state and local programs have focused on thinning forests, particularly those on the edge of cities and towns, but tens of millions of acres remain to be treated.

Rey said he hopes local communities will impose zoning restrictions on building homes in fire-prone forests, the way flood plains are regulated.

Until they do and thinning projects catch up with the fuel build-up, andquot;I think on balance we are going to continue to see some more difficult fire years,andquot; he said.

Meanwhile, Forest Service firefighting spending is skyrocketing -- from $179 million in 1997 to $1.5 billion in 2006.

The agency figures more than half that money goes to wildfires threatening homes, according to a federal audit last year.

Fire spending, including prevention, amounted to 40 percent of the Forest Service budget last year, and is projected to rise to 48 percent in 2008, prompting the agency to consider letting more fires burn rather than trying to put them all out.

Mangan noted that burnovers are not even the biggest category of firefighter deaths. Since 1990 motor vehicle accidents, heart attacks -- particularly among aging volunteers -- and aircraft crashes killed more.

The 2006 deaths included eight in aircraft crashes, seven from burnovers, four from motor vehicle accidents, three from heart attacks, one from a falling tree and one who fell off a lookout tower.

It all goes back to trying to put out nearly every fire, rather than letting more burn, said Andy Stahl, executive director of Forest Service Employees for Environmental Ethics.

andquot;We're sending more troops into these most dangerous fires, so of course we are going to lose more,andquot; he said.

Kent Maxwell, a founder of Colorado Fire Camp in Salida, Colo., a nonprofit wildland firefighter school, said every time there is a major burnover, new safety rules are imposed, yet fatality reports still cite firefighters' failing to react to known dangers.

andquot;Oftentimes firefighters, particularly during a long season, feel it's just another day on another fire,andquot; Maxwell said.

Timothy Ingalsbee, executive director of Firefighters United for Safety, Ethics and Ecology, said the number of safety guidelines firefighters must know is up to 133.

andquot;That's just too much -- sensory overload,andquot; he said. andquot;Most of the thrust in the safety programs falls on the shoulders of the ground-level grunts, but rarely are the policies that drive fire suppression in the first place addressed.andquot;