UPDATE: The death toll in the northern California fire has grown to 71, and over 1,000 people are missing, Sacramento-based NBC affiliate KCRA reported.
The search for victims of a catastrophic blaze that reduced a northern California town to ashes intensified on Thursday and authorities said the list of those reported missing had expanded to more than 600 in the deadliest wildfire in California history.
At least 63 people have been confirmed dead so far in the Camp Fire, which erupted a week ago in the drought-parched Sierra foothills 175 miles (280 km) north of San Francisco and now ranks as one of the most lethal single U.S. wildfires since the turn of the last century.
Authorities attributed the high death toll in part to the staggering speed with which the wind-driven flames, fueled by desiccated scrub and trees, raced through Paradise, a town of 27,000 residents.
WATCH: The death toll in the Camp Fire in northern California has risen to 63 after seven more bodies were discovered Thursday, officials said
Nearly 9,000 homes and other buildings, including most of the town, were incinerated last Thursday night, hours after the blaze erupted, according to the California Department of Forestry and Fire Protection (Cal Fire).
What was left was a ghostly, smoky expanse of empty lots covered in ash and strewn with twisted wreckage and debris.
WATCH: Drone shows extent of devastation from California wildfire
Thousands of additional structures were still threatened by the blaze, and as many as 50,000 people remained under evacuation orders. An army of firefighters, many from distant states, labored to contain and suppress the flames.
The revised official roster of 630 individuals whose whereabouts and fate remained unknown is more than double the 297 listed earlier in the day by the Butte County Sheriff’s Office.
Sheriff Kory Honea said the list of missing https://bit.ly/2BaiYxy would continue to fluctuate as more names are added and others are removed, either because they turn up safe or come to be identified among the dead.
The higher confirmed death toll, and rising number of people classified as unaccounted for, were revealed at an evening news briefing by Honea, who said the remains of seven more Camp Fire victims had been located since the previous tally of 56 was announced on Wednesday.