CONIFER, Colo. — The residents of about 900 homes have been evacuated and more are under threat today as a wind-driven wildfire scorched a mostly rural area in the mountains southwest of Denver.

The blaze, several miles and mountain ridges west of the city’s tightly populated southwestern suburbs, has destroyed 15 to 25 structures, at least five of which were homes, authorities said.

A body was found late Monday but investigators have yet to determine the cause of death. The victim wasn’t a firefighter or emergency responder, Jefferson County sheriff’s spokeswoman Jacki Kelley said.

The fire spread to nearly 5 square miles within a matter of hours, spurred by high wind gusts that prevented air crews from helping firefighters on Monday. Forecasters said gusts were expected to be lighter today, though a period of stronger winds was expected in the afternoon.

“The wind will really tell the story today,” Kelley said.

The wildfire may have been a prescribed burn from last week that sprang back to life because of the gusts, Kelley said. Prescribed burns are usually done to thin out vegetation to reduce the chances of a major wildfire.