BOULDER, Colo. (AP) -- Firefighters were able to contain about half of a small but potentially dangerous wildfire just west of downtown Boulder, Colorado, that forced hundreds to flee and sent up thick plumes of black smoke.
Boulder County Sheriff's Cmdr. Mike Wagner said the blaze may be human-caused and that hikers and transient campers frequent the area where it erupted — a wooded, mountainous place a couple of miles from Pearl Street, the shopping and dining hub in the heart of the university city. Officials ruled out any lightning strikes or downed power lines, Wagner said.
The fire started in the Sunshine Canyon area, which is dotted with expensive homes and rustic mountain residences. Dead trees exploded and sent black smoke skyward.
Residents of 426 homes under mandatory evacuation orders spent the night with friends and family or at the Red Cross shelter downtown. A decision on whether some might be able return wouldn't be made until later Monday, according to the Boulder Office of Emergency Management.
No structures were damaged by the 62-acre fire, though crews were spending the night focusing on protecting homes and monitoring the blaze's perimeter. Officials worried that stronger wind gusts could fan the flames overnight, and residents of 836 homes were told to be ready to leave if conditions worsened.
"It's always alarming and always on your mind, but it's not an uncommon sensation around here," said Seth Frankel, whose neighbor told him early Sunday about the fire less than a half-mile from his home.
Frankel and his wife, a Boulder native, and their three daughters have dealt with fires and floods before. In 2010, a wildfire destroyed nearly 200 houses in the area west of the city, home to the University of Colorado, Boulder.
On Sunday, about 250 firefighters from agencies as far away as Colorado Springs fought the blaze, backed by water-dropping helicopters and aircraft dropping flame-red sheets of fire retardant. Wagner said the air presence would likely be downsized on Monday as ground crews focus on encircling and mopping up the blaze.
Conditions were tinder-dry in many parts of Colorado's eastern Rocky Mountain foothills and the Eastern Plains, and municipalities imposed fire bans under what are known as "red flag" warnings.