THOUSAND OAKS, Calif. — Even in a state hardened to the ravages of wildfires, the infernos that raged at both ends of California on Friday were overpowering. At least nine people were killed, including several who died in their cars in a retirement community called Paradise. Malibu mansions burned. And in the neighborhood in Thousand Oaks where a gunman had killed 12 people in a crowded bar earlier in the week, survivors now fled the flames.

The fire-prone state was battling three major fires, one in the northern Sierra and two west of Los Angeles. In the northern town of Paradise, the ruins of houses and businesses smoldered throughout the day, while in Southern California, tens of thousands of residents fled their homes and jammed onto highways. Exotic lemurs and parrots were packed up and carried away to safety as fires ringed the Los Angeles Zoo in Griffith Park.

Officials estimated that the blaze in the north, called the Camp Fire, had destroyed a staggering 6,700 structures — most of them residential. Such vast devastation would make it the most destructive fire in modern state history.