Wildfires fanned by strong winds forced the evacuation on Thursday of more than 30,000 residents of two Colorado municipalities in Boulder County.

The Boulder County Office of Emergency Management announced evacuation orders for Superior and Louisville, urging residents to act quickly to escape danger.

The Louisville Police Department told residents to evacuate east or north.

Forceful wind gusts of more than 70 miles per hour and numerous road closures complicated evacuation efforts. Video that circulated on social media showed cars moving in thick gray and orange plumes of smoke, and confused grocery shoppers being evacuated into the smoky haze outdoors.

An emergency operations center was activated to address three active fires, according to the Office of Emergency Management. The fire south of the city of Boulder that is threatening Superior and Louisville is called the Marshall Fire.

Nearby towns are on high alert about the rapidly spreading fires. While there were not yet active fires in the city of Broomfield, the police announced pre-evacuation orders.

“Prayers for thousands of families evacuating from the fires in Superior and Boulder County,” Gov. Jared Polis said on Twitter. “Fast winds are spreading flames quickly and all aircraft are grounded.”

This is a developing story.