LOS ANGELES (AP) – Fierce Santa Ana winds raked Southern California on Monday, toppling power lines, big-rigs and trees, stirring up huge dust clouds and raising fire danger across the region.

More than 40,000 Southern California Edison customers were blacked out at times during the day, and some 8,400 were still without power by night, the utility said. Three-hundred personnel were working to restore service.

In Los Angeles, a few thousand customers were without power Monday night, mainly in the San Fernando Valley area of the city, said Winifred Yancy, spokeswoman for the Los Angeles Department of Water and Power.

A portion of Van Nuys lost power around 4:30 p.m., but work crews restored electricity by 8 p.m. to about 2,000 customers, Yancy said.

Toppled trees caused damage to cars and homes.

In Los Angeles, a tree knocked down on a residential street crashed into the front of a pickup truck and downed power lines.

In Orange County, the wind uprooted a eucalyptus tree on the sixth hole of the San Clemente Municipal golf course, sending it crashing into the bedroom of a condominium. No one was injured.

Fire officials also received dozens of calls from residents along foothill communities who reported ash swirling around their homes. The ash was left over from September’s Williams and Curve fires in the Angeles National Forest, said Los Angeles County fire inspector Ed Osorio.

The winds flowing out of the interior and offshore were unleashed by upper-level low pressure over southeast California in combination with a strong high-pressure building over the Great Basin, the National Weather Service said.

The weather service clocked wind gusts of 77 mph on the east side of the Verdugo Mountains, just north of Glendale. In Burbank, a gust was recorded at 53 mph.

Powerful gusts were expected to remain a problem through Tuesday night.

“Red Flag” warnings were issued because of the strong drying effect that dramatically increased fire danger levels. Humidity levels plunged to the teens and single digits by afternoon, weather officials said.

State forestry and fire officials ordered special staffing in the Riverside region east of Los Angeles due to the fire threat.

The winds pushed out to sea and forecasters warned that east-facing harbors and landings of the Channel Islands could be affected by a significant wind-driven swell.