At least 8,400 homes, businesses and other structures have been destroyed by wildfires in northern California's wine region, the state's fire service said Friday, dpa reported. The death toll currently stands at 42, with most recorded in Sonoma County where officials counted 22 fire-related deaths. The so-called Tubbs fire, which is still burning in Sonoma County, has destroyed a record 5,300 structures and scorched almost 15,000 hectares. The blaze is now over 90 per cent contained, fire officials said. The Tubbs fire alone is one of the most destructive wildfires in the state's history. Nearly 10,000 firefighters are still battling nine large fires across the region. The number is down from 21 during the height of the fires. The blazes, which wiped out entire neighbourhoods, have burnt over 99,000 hectares. Firefighters have been making progress and Calfire said most of the blazes were either 80 or 90 per cent contained. Just over 15,000 people are still waiting to return to their homes, according to Calfire.