Due to rapidly growing flames fanned by 100-mph winds that burned down hundreds of homes in Denver, two northern Colorado cities were forced to evacuate on Thursday.

Over 20,000 Louisville residents and nearly 13,000 Superior residents were instructed to evacuate immediately, according to the Boulder County Office of Emergency Management.

¨Leave now, there is no time to lose,¨ the National Weather Service (NWS) office warned.

Six individuals were sent to the hospital almost away, and despite the lack of information on material damage, multiple buildings, homes, and vehicles have already been damaged.

The Boulder County Office of Emergency Management has issued an Evacuation Order for the whole town of Superior, Colorado. The South Boulder Recreation Center will serve as an evacuation stop. The Superior Community Center is not a designated emergency shelter.

The YMCA in Lafayette, Colorado, is one of the evacuation points for Louisville residents. People will be able to rest at the Flatirons Community Church's Lafayette site, but no overnight stays will be permitted.

Residents were advised to evacuate "immediately" and head east, according to the Louisville Police Department.

The fire, which is located northwest of Superior, is one of several that began on Thursday. According to The Associated Press, some of the flames were started by downed powerlines. A fire has also forced the closure of a section of US Highway 36 near the scene.

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