The Ryan Fire exploded over the weekend, growing from 3,000 acres on Friday to 19,000. The fire is burning mostly in Wyoming.
Jesper Joergensen, a Denmark native, told police that he started a fire to burn trash, and then that he was grilling in a fire pit.
Record-breaking heat last week and over the weekend hasn't helped firefighters battling wildfires across the state.
Hot weather and wind caused the Silver Creek Fire to flare up Wednesday evening, growing at least 1,000 acres.
Hot and dry weather with windy conditions helped make this the worst fire season in Colorado since 2002.
The lawsuit was filed before the Forest Service has completed its own official investigation into the fire's cause. It claims that train management was “careless."
A study from the University of Idaho found that wildland firefighters are fatigued and have delayed reaction times, which may be a result of not getting enough sleep. The study leaves more questions than answers.
Higher temperatures and low humidity may challenge firefighters later this week. Otherwise, fire restrictions and fires overall are slowing down in Colorado.
Smoke from fires continues to hover above the Front Range and northwestern Colorado on Friday. The most active wildfires in the state have grown little this week.
Wildfires in California have killed at least eight people and destroyed more than a thousand homes.