Search teams looked for two missing people on Sunday in the snow-covered but still smoldering debris from a massive Colorado wildfire, while people who barely escaped the flames sorted through what was left after the blaze and investigators tried to determine its cause.

The flames ripped through at least 9.4 square miles (24 square kilometers) and left nearly 1,000 homes and other buildings destroyed in suburbs between Denver and Boulder. It came unusually late in the year following an extremely dry fall and amid a winter nearly devoid of snow. Experts say those conditions, along with high winds, helped the fire spread.