The Detwiler Fire near Yosemite is the one sending smoke into the Truckee Meadows today, creating unhealthy air quality over much of Northern Nevada. The fire has burned more than 45 thousand acres, and about 4,000 people have been evacuated, including the entire city of Mariposa a few miles west of the park. Eight structures have been destroyed. Only a small level of containment has been reached as more than 22 hundred firefighters battle the flames. The Washoe County Health Department says people with heart or lung disease, older adults, and children should avoid prolonged or heavy exertion. Everyone else should reduce prolonged or heavy exertion.