Fire crews began to make slow progress against wildfires that have killed at least 31 people in Northern California’s wine country as officials continued the grim search for more bodies amid the ashes.

In Santa Rosa, the hardest hit by the fires, officials said they were stunned by the scale of the destruction. An estimated 2,834 homes were destroyed in the city of Santa Rosa alone, along with about 400,000 square feet of commercial space, Santa Rosa Mayor Chris Coursey said in a news conference Thursday afternoon.