The Bolt Creek fire ignited early Saturday morning, and quickly spread to 7,600 acres by Sunday, prompting evacuations around the small town of Index in the western foothills of the Cascade Mountains. The attitude of fire crews was largely defensive as officials said the late summer blaze threatened hundreds of homes and other structures but had destroyed only one outbuilding as of Sunday. No injuries or deaths were reported. Peter Mongillo, spokesman for Snohomish Regional Fire and Rescue, said about 500 firefighters battled the blaze through Sunday. He said crews have used helicopters to drop water, but have not brought in planes carrying fire retardant chemicals because windy conditions make those flights more dangerous. An 18-mile section of Highway 2 remained closed between east of Gold Bar and Skykomish, with no estimate for reopening. The fire, which was burning in steep and rugged terrain, was 0% contained as of Sunday afternoon. Many residents of Index and nearby communities fled their homes to stay with friends or family, or to stop at evacuation centers staffed by the Red Cross and other volunteers. The Virginia and Jay Held arrived Sunday morning at an evacuation center in the town of Startup, carrying more passengers than expected from wildfire evacuees. Eleven chickens — including several chickens — rustled anxiously in the back of their station wagon as it rolled into the parking lot with a flat tire. “We call it the Ford Coop,” Jay Held said as a friend helped him change the tire. “This is the mobile chicken evacuation unit.” On Sunday morning, the couple had returned to their home along Mount Index River Road — a small community across the river from Index — only to find that the power had been cut shortly after they arrived. Although they did not receive an evacuation order, their neighbors across the river did. That, along with the dystopian orange sun covered in an unrelenting tarpaulin of smoke ash, was reason enough to get outside. “We just have to leave everything out there and hope the fire doesn’t get that far,” Virginia Held said. The couple brought with them tools, a generator and enough supplies to last several days. “That’s what we do,” he said. “Playing the waiting game.” The mandatory level 3 evacuation order is in effect for an area stretching from Index to Skykomish, covering about 500 structures, according to Mongillo of Snohomish Fire and Rescue. The Snohomish County Sheriff’s Office said Sunday that only about half of those in the evacuation zone had left the area. “We ask them to reconsider. The fire remains active. We need everyone’s help to protect lives today,” the department said in a tweet. A Level 2 evacuation has been issued for the area to the immediate west between Index and Zeke’s Drive-In, meaning people should be ready to leave immediately. A Level 1 evacuation has been put in place for the Gold bar, meaning residents should be prepared to evacuate if conditions worsen. Jim Cahill, a spokesman for the Department of Natural Resources, called the Bolt Creek fire an “unusually large fire in recent history in this area.” He said crews to scout the terrain for areas where fire lines can be established, using existing roads and trails as starting points, he said. “They are still moving forward with an emphasis on protecting structures, infrastructure, homes and public safety,” he said. Devastating wildfires and suffocating blankets of smoke have become an expected, if not desired, feature of summers in the western U.S., exacerbated by a drought scientists predict will become more severe as greenhouse gas emissions from cars, industries and power plants fuel climate change. The Bolt Creek fire is one of 19 large active fires burning in the Pacific Northwest, according to the Northwest Interagency Coordination Center. The Goat Rocks fire in Lewis County had burned more than 2,800 acres, prompted evacuations and closed both directions of Highway 12, according to the U.S. Forest Service and the state Department of Transportation. Nationally, 92 large wildland fires have burned nearly 728,000 acres this year, mostly in northwestern states, according to the National Interagency Fire Center. Smoke from wildfires drifted into the Seattle area, causing one of the region’s worst air quality days in two years, according to preliminary data from the Environmental Protection Agency. Air quality is also at unhealthy levels in the Tri-Cities, Spokane and Pullman areas due to wildfires in Idaho, Montana and Oregon. Cooler weather is expected later this week, according to the National Weather Service, with light rain possible in the Seattle area. Those temporarily displaced by the Bolt Creek Fire were hoping the weather would not push the fire further west. Randy Ladowski, 34, and his girlfriend spent the night outside an evacuation center at the Evergreen State Fairgrounds in Monroe, in a makeshift structure in his truck that included a bed, kitchen, composting toilet and solar panels. Ladowski works as a rope access technician in Seattle but lives in Index. He was busy moving his climbing and ski equipment from his car to the trailer Sunday morning. Before evacuating, Landowski said he took one last walk around town with his friends and neighbors. “Everybody was kind of light,” he said. “That’s when we started to realize that this could be it.” Ladowski had just managed to sneak into Index on Sunday morning to pick up his motorcycle and park it at the Gold Bar. “I cycled around town and then said, ‘I’ve got to go.’ I’m going to start crying,” she said. Seattle Times staff reporters Daniel Gilbert and Esmy Jimenez contributed to this report.