Why the Esperanza Fire Is So Deadly

The deadly Esperanza wildfire in southern California killed four U.S. Forest Service firefighters Thursday; a fifth remained alive on life support. Fueled by winds gusting to 40mph, the fire burned through 24,000 acres, adding to a record U.S. wildfire season. So far this year, fires have burned 9.4 million acres, topping 2005’s record of 8.6 million acres, according to the National Interagency Fire Center.

The four firemen of Engine Crew 57 died Thursday morning as they fought to save a house from onrushing fires near Twin Pines, Calif. Engine Capt. Mark Loutzenhiser, 44, left five children. Also killed were Jess McLean and Jason McKay, both 27, and Daniel Hoover-Najera, 23. Pablo Cerda, 23, lay in critical condition in a local hospital with burns over 90 percent of his body. Doctors called his prognosis poor. The four fatalities were the worst single episode in California since four firefighters died in 1979 in a fire in central California.

The Esperanza fire was fueled mostly by chaparral, dense scrub wood that resides in steep, semiarid country. It is highly flammable and difficult to fight, according to Ken Pimlott, an assistant deputy director of the California Department of Forestry & Fire Protection, who spent years fighting fires in southern California. He spoke to NEWSWEEK’s Andrew Murr about the challenges of chaparral fires. Excerpts:

NEWSWEEK: Why are chaparral fires so dangerous?

Ken Pimlott: For a number of reasons. For one thing, the chaparral plant community is very flammable. It’s a combination of a number of plant species like manzanita and chamise whose leaves are covered with a waxy coating that holds in water, but it is very flammable. And as those plants mature, there’s a significant dead component within the plants. It’s basically kindling wood inside the flammable waxy material. Then you get into the wind conditions we’re having right now: the Santa Ana winds. They are warm and dry winds that blow off the desert. When those wind blows, it dries down the vegetation even more. The relative humidity of the air can get into the single digits, 5 to 10 percent, and the fuel moisture level gets down to around 3 percent. They are very strong. They blow up to 40 or 50mph, and they create a very fast-burning, high-intensity fire.

It’s been reported that the Esperanza fire overran the firefighters. How fast can these fires move?