A large grass fire has prompted major evacuations in two towns outside Boulder, according to the Boulder Office of Emergency Management. More than 500 homes have burned and over 21,000 people in Louisville, Colorado, and 13,000 in Superior, Colorado, are under evacuations orders, which could continue to increase as strong winds across the state fuel the fire's spread. Over 1,600 acres have already been burned, Boulder County Sheriff Joe Pelle said Thursday in a news briefing. Over 370 homes in one subdivision have already been destroyed and another 210 have the potential to burn as the flames continue. Officials did not say how the Marshall fire began. "We know that people are anxiously waiting for word about the conditions of their homes and their neighborhoods," Pelle said. "I want to assure you that our fire personnel are working as hard as they can to save additional structures as we speak and when it's safe to do so, will start the emotional and painful process of assessing damages." Governor Jared Polis on Thursday declared a state of emergency, which will allow the state the access emergency funds set aside for disasters. Officials said the an additional grass fire, the Middlefork fire, was first reported around 10:30 a.m., but was quickly put out. The Marshall fire, which started at a similar size, grew quickly and is now an active threat. The flames are around 20 miles northwest of Denver. One emergency office has been minorly injured in the flame from flying debris in the air. At least six people have already been hospitalized for injuries from the Marshall Fire, CBS Denver reports. No fatalities have been reported, and Pelle said that due to the size of the fire and its threat to such a heavily populated area, officials are bracing for more injuries and fatalities. "The conditions around the Marshall Fire are still volatile and unsafe," Pelle added. "We'd encourage anyone in a mandatory evacuation zone to do so." Residents are encouraged to keep 911 lines open for major emergencies and direct all questions about burning routes and open roads to the Office of Emergency Management help line at 303-413-7730. Highway 36 was closed around 2 p.m in both directions because of fire activity and has no estimated time of reopening. Power was also cut to more than 34,000 customers in Superior and Louisville, according to emergency officials. At least two evacuation centers have been opened for residents at the South Boulder Recreation Center at 1360 Gillaspie Drive and the Lafayette YMCA at 2800 Dagny Way, which is taking pets.