An investigation into the cause of a 10-acre brushfire  near Dawson Canyon Road could begin today, now that the blaze has been  contained and brought under control, a Riverside County Fire Department  spokeswoman said.
      A line of vegetation was cleared around where the fire burned and the  smoldering embers were put out by about 8 p.m. Sunday, said fire department  spokeswoman Melody Hendrickson.
      No structures were threatened by the blaze, which was reported at 2:35  p.m. Sunday in the area of Dawson Canyon Road west of Stuart Drive, she said.
      Two air tankers and 124 firefighters were assigned to battle the fire.