Originally published October 20, 2009 at 3:18 p.m., updated October 20, 2009 at 4:19 p.m.
A fire of unknown origin blackened about 10 acres in a brushy North County field today, threatening several homes but causing no reported structural damage or injuries, authorities reported.
The blaze just west of the intersection of Cassou and North Twin Oaks Valley roads was reported about 2:15 p.m., said Rick Vogt, a battalion chief for the San Marcos Fire Department.
Ground personnel and crews aboard three Cal Fire aircraft -- a helicopter and two air tankers -- had the flames knocked down within 90 minutes, according to Vogt.
The cause of the fire was under investigation, he said.