Too many houses built too close together on the tinder-dry high plains between Denver and Boulder led to the record Marshall firestorm losses topping $1 billion, insurance industry researchers found this week as they sifted through ashes and charred ruins.

They were beginning an investigation, similar to work done after previous ruinous fires, including the 2012 Waldo Canyon fire west of Colorado Springs and the 2018 fire that destroyed nearly 19,000 structures in Paradise, California.

Their industry Insurance Institute for Building and Home Safety is developing a science of how fires burn through communities and what can survive as climate warming intensifies.

‘Spacing here was a problem, ‘ research engineer Faraz Hedayati said as he probed gaps less than 10 feet wide between former houses where radiant heat helped flames spread.