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 . Seven fires among the 22 counted Wednesday were contained . See where the fires are burning » . 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 could n'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 are n'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 .
Local and federal authorities probe suspected tornadoes , offer $ 70,000 reward . Wind speeds drop , humidity increases after Santa Ana winds change direction . President Bush signs major disaster declaration for Southern California . Home damage will likely top $ 1 billion in San Diego County , official says .