Updated: Saturday, October 14, 2017, 3:00 p.m.  

The multiple wildfires burning across a swath of Northern California have consumed more than 220,000 acres, while firefighters continue to make progress containing the fires. The causes are still under investigation.

The fires are burning from Napa and Sonoma counties out to Nevada County and up to Mendocino, and have killed 37 people, making these the most deadly fires in California history. Hundreds more people are still missing. More than 5,700 structures have been destroyed, which is nearly twice the previous most destructive fire in California, the 1991 Oakland Hills Tunnel Fire. On Monday, Governor Jerry Brown declared a state of emergency.

“October, November we do see some of our most destructive and damaging wildfires historically,” says CalFire information officer Heather Williams.

Fires that tear through neighborhoods and shopping centers have become more common as California’s population booms and development sprawls into vegetated areas.

“We saw how quickly these fires spread into these suburbs and communities,” says Williams, speaking of the Tubbs Fire in Santa Rosa.

Cumulatively, the current fires are also the deadliest. The second most deadly was Los Angeles’ Griffith Park Fire where 29 people died, followed by the Oakland Hills Tunnel Fire where 25 people perished.

In terms of acreage, the current wildfires rank at number 5 among the top 20 biggest. The largest California wildfire in history, the Cedar Fire, burned 273,246 acres and the twentieth biggest, Ventura’s Wheeler Fire, burned 118,000 acres. Combined, the fires burning in California right now total more than 220,000 acres.

“The thing we are seeing is that fire season is lasting longer,” says Williams, “it’s almost year-round now.”

The CalFire spokeswoman says it could be weeks or months before all the fires are fully contained and the true extent of the damage is calculated.

For continual fire updates, check KQED News.