Arson suspected in fatal blaze

Smoke from the fast-moving Esperanza fire is so heavy it blocks the sun in Banning.  (Irfan Khan / Los Angeles Times)

Flames from the Esperanza fire jump Highway 243 in Banning, forcing a fire crew to turn back Thursday morning.  (Irfan Khan / Los Angeles Times)

Smoke engulfs the surrounding area and a smoldering structure along Twin Pine Road.  (Irfan Khan / Los Angeles Times)

Ruins smolder along Twin Pine Road where a home once stood.  (Irfan Khan / Los Angeles Times)

Heavy smoke from the fast-moving Esperanza fire blocks the sun while a fast-moving brushfire blocks fire crew access via Highway 243.  (Irfan Khan / Los Angeles Times)

Fire consumes a structure along Twin Pine Road.  (Irfan Khan / Los Angeles Times)

CHP officer Randy Dopp closes Gorgonio View Road, which leads to the spot where three firefighters lost their lives fighting the Esperanza fire.  (Irfan Khan / Los Angeles Times)

Firefighting helicopters drop water onto the wind-whipped blaze covering hundreds of acres.  (Karen Tapia / Los Angeles Times)

People load a horse into a trailer as they prepare to evacuate the area.  (Karen Tapia / Los Angeles Times)

Ed Menendez, 16 months, sits in the back seat with the family pets after his family was evacuated.  (Karen Tapia / Los Angeles Times)

A structure continues to burn in the Banning area after fire swept through.  (Karen Tapia / Los Angeles Times)

A water dropping helicopter douses flames burning close to a pagoda-like structure during the Espinoza Fire in Poppet Flats.  (Gina Ferazzi / Los Angeles Times)

Investigators (bottom left) work the scene where four firefighters were killed after they were overrun by the fast-moving Esperanza fire in Poppet Flats.  (Gina Ferazzi / Los Angeles Times)

A burned-out fire engine smolders on the property where four firefighters were killed and one critically injured after they were overrun by fire at this home in Poppet Flats.  (Gina Ferazzi / Los Angeles Times)

Riverside County investigators carry the body of one of the four fire fighters killed after they were overrun by fire at this home in Poppet Flats.  (Gina Ferazzi / Los Angeles Times)