Colorado fire: Smouldering underground coal mines investigated as cause of blaze that destroyed 1,000 homes

Authorities in Colorado are investigating whether smouldering coal mines, which ceased operations decades ago, may be the possible cause of a devastating fire which destroyed 1,000 homes.

The Marshall Fire ignited on 30 December and quickly whipped into a raging inferno due to 100mph winds in southern Boulder County. The fire left one man dead and a 91-year-old woman remains missing.

Hundreds of structures were lost in the towns of Louisville and Superior, northwest of Denver. It is the costliest wildfire in state history in terms of home damage.

While wildfires are rare at this time of year, the climate crisis is making winter warmer across most of the US and exacerbating drought conditions. Denver hit a high of 73F on 4 December – tying a record set in 1973 – and broke an 87-year-old record for the number of days without snowfall last month.

The Boulder County Sheriff’s Office are exploring a range of possible causes for the fire. Last week, it was suggested that the 19th-century coal mines, which have been burning underground for years, could have reached the surface due to the windstorm.

“We are investigating any and all potential causes of the fire including coal mines in the area, power lines, human activity, etc.,” Carrie Haverfield, a sheriff’s office spokesperson, told CBS Denver.

CBS Denver also reported that sheriff’s department patrol vehicles were recently seen in the vicinity of two closed coal mines, known as Marshall No.1 and Marshall No.2.

The sheriff’s office had no updates on the investigation when contacted byThe Independent on Tuesday.

The Marshall No 1 and Marshall No 2 mines are located near the Marshall Mesa trailhead, several miles to the west of the towns which caught on fire.

There are approximately 1,736 known abandoned coal mines across the state, according to a Colorado Underground Coal Mine Fires 2018 Inventory Report.

The inventory listed 38 coal mines with some level of fire risk and in 2018, Marshall 1 and 2 were found to be of low risk.

However the report noted: “This fire has behaved erratically in the past, so it is recommended that it be monitored annually to check for increases in fire activity.”

According to federal data, there are nearly 5,200 coal-related abandoned mine sites in the US, totalling about $3billion in health and safety problems, and more than $2bn of general welfare, environmental and non-coal problems.