RANCHO CUCAMONGA, California (CNN) -- The wind-swept Grand Prix fire burned a vivid red line on the edge of the eastern suburbs of Los Angeles early Saturday as more than 2,000 firefighters battled to gain the upper hand.
The blaze, which started Tuesday, has already torched nearly 13,000 acres and threatens electrical lines that provide power to about a million customers.
Late Friday, fire crews took advantage of a lull in the hot, dry Santa Ana winds and sent fixed-wing aircraft to dump flame retardant on the rapidly swelling blaze.
But with red flag advisories warning of 25 to 35 mph winds with gusts up to 45 mph Saturday, the planes will be grounded Saturday.
As of Saturday morning, the flames were 19 percent contained, and evacuations east of Day Creek and north of I-15 had been lifted.
The fire has consumed at least one home, four travel trailers, two cars, one boat and trailer and a U.S. Forest Service helicopter that had been grounded because of mechanical problems, the Southern California Interagency Incident Command reported.
The San Bernardino Fire Department said the fires had destroyed at least three homes, but officials aren't sure how many other structures have been destroyed, because flames are still engulfing evacuated areas.
More than 2,000 evacuated
More than 2,000 people have been evacuated from areas affected by the fire, which initially forced the closure of two interstate highways .Interstate 15 has since reopened, while I-210 is closed.
Gov. Gray Davis told reporters in Rancho Cucamonga Friday afternoon that more firefighters were on alert to be sent to the area, and 15 more helicopters are preparing to go to the region.
"The great thing about California is, in every natural disaster we all work together ... we're all pulling in the same direction, trying to get people through the day," Davis said.
Smoke and debris from the fire were seen 40 miles to the west in Hollywood, CNN correspondent Miguel Marquez reported.
Thursday the Santa Ana winds whipped the then two-day old fire into a frenzy and it swept down Day Canyon faster than expected, Rancho Cucamonga spokesman Duane Baker said.
"The wind certainly makes this a fast-moving situation," Baker said. "It makes it a much more fluid situation than it has been."
Steep rugged terrain has hampered firefighters trying to get close to the flames.
U.S. Forest Service Information Officer Michael Esperza said authorities have ruled out natural or regional causes, leading them to suspect arson