About 50 hikers spent a second night at a wilderness resort near Fresno, Calif., on Monday with all escape routes cut off by the growing Creek Fire in the Sierra National Forest, an “unprecedented disaster” that ravaged the state over the holiday weekend and nearly doubled in size on Monday alone, fire officials said.

Fresno Fire Battalion Chief Tony Escobedo initially said at a news conference late Monday that one person had died in the fire, but the Fresno County Sheriff’s Office later clarified that an older man died due to a “medical episode” after emergency medical services were unable to respond because of the fire conditions.

Escobedo told reporters that the smoke from the fire, which reached up to 135,523 acres with zero percent containment as of late Monday, made it impossible for the Fresno Fire Department’s helicopters to rescue the hikers, who have been sheltering at the Vermilion Valley Resort since Sunday night. The rescue operation was suspended around midnight after the helicopters were again unsuccessful in reaching the trapped people, who authorities said are not in immediate danger. Rescue attempts are expected to resume Tuesday morning.

“The ongoing effort is to try to get those people to a safe location,” Escobedo said.

The explosive fire, featuring towering clouds of smoke that probably triggered lightning and fire tornadoes, has caused mass evacuations of an estimated 25,000 to 30,000 people, according to authorities. More than 1,000 fire personnel have continue to fight the fire. Although Cal Fire reported late Monday that 65 structures are listed as destroyed in the fire, according to the Fresno Bee, almost 5,300 structures remained threatened. Nick Truax, the incident commander for Cal Fire, told reporters that there has been a “pretty heavy structure loss,” including the destruction of homes.

News of the rescue efforts comes after California Air National Guard had rescued more than 200 people over the weekend when evacuation routes were cut off, reported The Washington Post’s Jason Samenow.

“This is an unprecedented disaster for Fresno County,” Fresno County Sheriff’s Office Lt. Brandon Pursell told reporters Monday. He later added: “This is one of the largest and most dangerous fires in the history of Fresno County. I don’t think everyone understands that. Playing that game of ‘how long can I wait’ is just foolish.”

At a news conference of local, state and federal officials Monday evening, Dean Gould, spokesman for Sierra National Forest, reeled off several past large wildfires in the region before concluding that the Creek Fire looked to be the most aggressive to date.

“This one is in a class by itself,” Gould said. “At least it has been the last couple of days.”

The Creek Fire erupted amid one of California’s hottest weekends ever observed, with temperatures climbing to 121 degrees in Los Angeles County. The U.S. Forest Service announced that all national forests in Southern California would be temporarily closed because of the increased fire danger. Officials with the Forest Service said that with the fire conditions in the region and the weather worsening, “we simply do not have enough resources to fully fight and contain every fire.”

With the weekend blazes, California wildfires have now burned more than 2 million acres this year, the most burned on record in a single season since modern records began more than three decades ago, according to Daniel Swain, a climate researcher at the University of California at Los Angeles.

“I have no doubt just as in those past [major fires], we’re going to get through this together as well,” Gould said.