LOS ANGELES (AP) _ The dreaded Santa Ana winds raked the region Thursday with gusts of up to 75 mph that fanned fires destroying 21 homes, snapped power lines, toppled structures and damaged Rose Parade floats.

More than two dozen additional homes and buildings suffered damage in the blazes but no serious injuries were reported, authorities said. Gusts toppled six trucks on highways to the east and cut power to more than 300,000 people.

''We lost everything - the house, the cars,'' said Dan Hanlon, 49, of La Verne, who fled with his wife. ''We were lucky to get out. We had to drive through flames.''

Generated by high pressure over Idaho and a low over Baja California, winds swept much of California and Nevada but were most destructive in the Los Angeles basin and to the east, where they roar down from the desert through the mountain ranges and become known as the Santa Anas.

Fifteen homes burned up and 10 other homes and six commercial buildings were damaged in Baldwin Park, 20 miles northeast of Los Angeles, when 75 mph gusts snapped power lines shortly after midnight and ignited a fire at Allan Paper Co.

''We saw sparks, showers of sparks, like rain,'' said Ruben Cabadas, 18, recounting his family's flight from their home as its ruins smoldered.

The blaze was contained at daybreak, said Inspector Chuck Gutierrez of the Los Angeles County Fire Department.

Damage to the Baldwin Park area was estimated at $4.5 million, said Los Angeles County Fire Inspector Joe Silva.

Six homes were destroyed and eight damaged in La Verne, 30 miles east, by a fire believed caused by a downed power line, said Silva. About 300 people were evacuated before the 150-acre blaze was contained. He said earlier damage totals of 10 homes destroyed and 15 damaged had been scaled back after a thorough inspection.

''It literally rained embers across roofs,'' said firefighter Ron Sillo.

An artificial Christmas tree wrapped in colored lights and tinsel lay on the driveway of Roy and Elinor Livingston's home, the only thing salvaged from the ruins.

Awakened by a neighbor, the couple found a row of palm trees and a nearby home ablaze, and battled fires on their roof until they were overwhelmed.

''It was just like the air was full of these giant sparks,'' said Mrs. Livingston, 56.

Four homes were slightly damaged by a fire that moved from Eagle Rock along a ridge into Glendale before it was contained this morning, said Los Angeles Fire Department spokesman Jim Wells. Several schools were closed.

In the San Fernando Valley community of Chatsworth, six men were arrested for investigation of arson as firefighters doused a five-acre brushfire of suspicious origin about noon, Wells said. The men weren't immediately charged, Wells said.

At Huntington Library, Art Gallery and Botanical Gardens in San Marino, a popular tourist stop, winds toppled 10 trees, eight large decorative vases and two bronze sculptures, said spokeswoman Catherine Babcock. She had no damage estimates.

Gov. George Deukmejian said in Sacramento that the Office of Emergency Services had opened and he pledged any assistance needed to fight the fires.

The National Weather Service issued wind warnings through Thursday night, advising of winds from 25 mph to 35 mph in Los Angeles and up to 45 mph in the valleys, with gusts of 60 mph or more below the passes and canyons.

Five floats being built for Pasadena's Rose Parade were damaged when a giant tent housing them in Azusa blew down, said Chuck Edwards of Fiesta Parade Floats. Initial damage estimates for just two floats was at least $40,000. The floats' chicken-wire constructions, crushed by falling beams, can be rebuilt in time for the Jan. 2 event, Edwards said.

Gusts toppled big-rig trucks on two interstate highways in the San Bernardino area but there were no serious injuries, said Highway Patrol dispatcher Ruth Sanchez. Blowing dust cut visibility to zero on Highway 60 in Moreno Valley.

The San Bernardino County sheriff's aviation unit was grounded at Rialto Airport, where gusts were recorded at 58 mph, said Sgt. Vic Brimmer.

Wind collapsed a three-story apartment building under construction late Wednesday in Rancho Cucamonga and blew roofs off two homes, said city emergency services coordinator Marti Higgins.

More than 300,000 Southern California Edison customers lost power but most service was restored by Thursday morning.

An additional 28,000 households in Los Angeles sustained overnight power outages, said Mindy Berman, spokeswoman for the Department of Water and Power.

Strong winds also hit other parts of the state overnight. Gusts to 45 mph were recorded at Travis Air Force Base near Sacramento and parts of the San Francisco Bay region, the National Weather Service said.

In Yosemite National Park, about 200 people were temporarily evacuated because of the threat of falling trees, said spokeswoman Kathy August. Gusts were clocked at 50 mph in parts of Yosemite Valley.

The high pressure system causing the winds was expected to continue into next week, pumping more Santa Anas into Southern California, the National Weather Service said.