OCCIDENTAL, Calif. - Authorities say four men were injured in an explosion at a Sonoma County conference center that apparently occurred when a spark ignited methane in a septic system.
The Press Democrat of Santa Rosa reports that one of the victims suffered third-degree burns in Wednesday's blast at the Alliance Redwoods Conference Grounds near Occidental.
The others had first and second-degree burns. One of the men also injured his eye.
Fire officials say workers were draining septic tanks and then filling them with gravel when a jackhammer they were using caused a spark that triggered the blast.
Two of the victims were taken to Santa Rosa Memorial Hospital.
Another two were taken to Palm Drive Hospital in Sebastopol.
Information from: The Press Democrat, http://www.pressdemo.com