COLORADO SPRINGS, Colo. (AP) -- The fire chief in Colorado Springs says his crews have been making heroic efforts and saved many homes as the 24-square mile Waldo Canyon wildfire continues to blaze in the foothills west and north of the city.

Constantly shifting winds have made the battle a difficult one for firefighters, but Chief Rich Brown says their "triage" strategy inside the suburban neighborhoods is helping. Firefighters have been racing from one hot spot to the next, protecting houses adjacent to the ones in flames to prevent a domino effect.

Meanwhile, federal firefighters are working with U.S. Army bulldozer crews from nearby Fort Carson to create perimeter lines.

More than 30,000 residents have been forced to flee their homes and the list of evacuated neighborhoods continues to grow.

Crews are also fighting to keep the flames from reaching the U.S. Air Force Academy.

The full scope of the fire remains unknown, because the flames have been too intense and the smoke too thick for rescue workers to tell which structures have been destroyed and which ones are still standing. The mayor's office says the number of homes destroyed is at least in the dozens.