Arson is suspected in three small brush fires that erupted Monday in La Canada Flintridge, but investigators have been unable to pinpoint a cause of ignition, a Sheriff's Department spokesman said Wednesday.
"There were no incendiary devices found; there were also no natural sources of ignition found," said Deputy Richard Edwards of the Los Angeles County sheriff's arson-explosive detail.
The three fires burned about 4 acres. The first, near Foothill and Ocean View boulevards, briefly threatened homes but was put out before it could cause damage, a spokesman for the county Fire Department said.
The other fires burned about an acre each near Lasheart Drive north of Foothill and on Canalda Drive.
La Canada Flintridge City Manager Don Otterman said arson has been suspected in about 20 brush fires in the city over the past four years.
Monday's fires appeared to fall into the pattern of previous ones, he said.
Edwards conceded that the area has been plagued by arson, but would not link the fires into a pattern suggesting a single firebug.
"There's no question that we have more than one person," he said. "Usually we have copycats."