SAN DIEGO, California (CNN) -- Conditions that created what California Gov. Arnold Schwarzenegger dubbed "the perfect storm for fire" eased Wednesday, helping firefighters gain ground against devastating Southern California wildfires.
A plane drops fire retardant on the fourth day of a wildfire pushed by winds through Pauma Valley, California.
Winds that gusted as much as 101 mph on Sunday dropped to about 30 mph Wednesday evening.
Meanwhile, the dry Santa Ana winds that have fanned the flames, changed direction and began blowing inland from the Pacific Ocean, increasing the humidity and easing the burden on almost 8,900 firefighters in the area.
But the destruction was taking its toll on the men and women on the front lines of the fires.
"It hurts us to have those homes lost. It hurts us to have those injuries. And it is frustrating for us to watch our community be devastated by this," said firefighter Andy Menshek.
As conditions improved, officials allowed people to return to communities that had been off-limits because of intense flames and dense smoke.
"It was home," said Mark Davis, whose two-story Rancho Bernardo house burned to the ground.
"It was us. We had been there 28 years, and it had a lot of our flavor."
The change in the weather also meant that firefighting aircraft -- grounded for most of the week by the winds -- could finally fly.
California Department of Forestry and Fire Protection Capt. Scott McLean called the droning sound of aircraft the "sound of joy."
"Their drops are hitting their mark because the wind is not there," he said.
The rate of burning had slowed significantly by Wednesday.
Still, the fire damage increased to 434,543 acres, said Gov. Arnold Schwarzenegger. Watch Schwarzenegger give a progress report »
That amounted to 679 square miles, or about 10 times the size of Washington, D.C.
By Wednesday evening, the largest fire -- the Witch in northern San Diego County -- was 10 percent contained.
It burned about 196,000 acres before combining with the smaller Poomacha blaze.
Others, such as the Buckweed Fire in Los Angeles County, were as much as 94 percent contained.
One large fire was a suspected arson.
The FBI and the Orange County Fire Authority are investigating the Santiago fire that has burned more than 19,000 acres.
All three of its points of origin have been declared crime scenes, said Jim Amornino, a spokesman for the Orange County Sheriff's Department.
A $70,000 reward is being offered for any information leading to the arrest of those responsible for setting the fire.
The blaze was about 50 percent contained after destroying 17 structures. Watch the raging flames of the Santiago fire »
The smaller Rosa fire in Riverside County, 70 percent contained at just over 400 acres, was also a probably arson, state officials said.
As the fire danger eased, residents were allowed to return to several neighborhoods surrounding San Diego: Del Mar Highlands, Encinitas, Solana Beach, Carmel Valley, Chula Vista and Otay Mesa.
Helicopters were back in the air over the Lake Arrowhead, California, area after all air activity had been suspended because of extremely smoky skies.
In nearby Running Springs, CNN's Ted Rowlands stood in the midst of charred, smoldering rubble strewn with potentially deadly power lines.
"It will be a while before these people will come back. When they do come back, unfortunately they'll have this pretty much to look at," he said Wednesday. Watch Rowlands describe a major battle with the flames »
About 500 homes were lost in the mountainous region in San Bernardino County east of Los Angeles. See photos of the fires »
"Yesterday we couldn't be here, because just this little flame and smoldering pieces of wood would be thrown by the intense winds. ... Now you can see the flames just basically burning themselves out," said Rowlands.
The fires have already destroyed 1,664 structures -- including 1,436 homes -- and they still threaten 25,000 more, Schwarzenegger said Wednesday.
The blazes have killed three people and left 40 hurt, he said.
The governor will fly over the area Thursday with President Bush, who signed a major disaster declaration Wednesday. Watch Bush emphasize the need to be responsive »
It'll speed federal dollars to people whose property losses aren't covered by insurance and will help local and state agencies pay for the emergency response.
The cost of homes destroyed by the wildfires is likely to top $1 billion in San Diego County alone, an emergency official said.
Federal help keeps arriving as officials promise a response based on lessons learned from Hurricane Katrina.
People left homeless by the fires can go online to apply for federal help at FEMA.gov, he said.
There were 76,000 people staying in the 42 shelters opened in San Diego County Wednesday morning, according to San Diego emergency spokeswoman Lynda Pfieffer.
Qualcomm Stadium -- home to the NFL's San Diego Chargers -- housed 11,000 evacuees at the peak of the disaster, but that number dropped to 5,000 Wednesday morning. Watch how evacuees are being taken care of at the stadium » E-mail to a friend
CNN's Kate Bolduan contributed to this report.
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