Utah is restricting fireworks as the largest wildfire in the nation continues to grow. The Cottonwood Fire in southern Utah started Monday and has reached nearly 111 square miles and is zero percent contained. Dry, windy conditions are fueling wildfire growth across much of the western United States. The National Weather Service issued a rare "Particularly Dangerous Situation" for a section of Utah, urging preparation for rapid fire growth. Red flag warnings also are in effect for parts of California, Nevada, Arizona, New Mexico, Colorado and Idaho. Authorities are urging caution as extreme fire conditions persist.