Residents of multiple northern Colorado towns were asked to evacuate Thursday after raging wildfires terrorized their towns, ultimately striking hundreds of homes and dislocating tens of thousands. The wildfires started early Thursday—at least one local law-enforcement official suspected multiple downed power lines led to small flames—and wind gusts of more than 100 mph caused the flames to spread through leafless trees and give the sky an orange filter. The blazes led the Boulder Office of Emergency Management to advise people living in the towns of Louisville, home to 21,000, and Superior, home to 13,000, to escape the wildfire’s path. The move was echoed by the National Weather Service of Denver/Boulder on Twitter: “If you are in Louisville, this is a life threatening situation. LEAVE NOW!” Both cities are about 20 miles northwest of Denver.

Six people were taken to a Colorado hospital with injuries from the flames, a UCHealth Broomfield spokesperson told ABC News. No deaths were immediately reported.