LOS ANGELES — Wildfires threatened hundreds of homes in the seaside hills and foothill canyons near Los Angeles early today, feeding on bone-dry brush in the midst of a heat wave expected to drive temperatures into triple digits.

As many as 1,500 people had to leave the wealthy seaside community of Rancho Palos Verdes overnight, while residents of about 870 homes were urged to voluntarily leave La Canada Flintridge, a dozen miles northeast of downtown Los Angeles on the foothills of the San Gabriel Mountains.

Water-dropping helicopters worked through the night, as the ominous red glow of flames illuminated the darkness. A lack of wind let the helicopters operate in the canyons, Los Angeles County fire Inspector Steve Zermeno said.

The Rancho Palos Verdes fire erupted late Thursday and spread rapidly. Hundreds of firefighters and their engines were deployed to protect homes in the fire's path.

Daybreak revealed an ash-covered landscape with no flames apparent. The burn area was officially listed at 100 acres with 35 percent containment, but Tripp said both numbers were expected to significantly rise when mapping was complete.

The wealthy communities on the Palos Verdes Peninsula south of Los Angeles are in an area known for horse trails, spectacular Pacific Ocean views, pricey real estate and exclusive golf clubs, including the Trump National Golf Club owned by Donald Trump.