A variety of photos showing avalanche incidents from several areas which are available on-line:
Kachina Peaks Avalanche Center (Arizona)
www.kachinapeaks.org/photogallery/main.php
Eastern Sierra Avalanche Center (California)
http://esavalanche.org/weather-resources
Sawtooth National Forest Avalanche Center (Idaho)
https://www.sawtoothavalanche.com/photos.php
Gallatin National Forest Avalanche Center (Montana)
https://www.mtavalanche.com/photos
Glacier Country Avalanche Center (Montana)
http://www.flatheadavalanche.org/education
Missoula Avalanche (Montana)
www.missoulaavalanche.org/photo-gallery/
Mount Washington Avalanche Center (New Hampshire)
http://www.mountwashingtonavalanchecenter.org/photos/tuckerman-ravine-photos/
Utah Avalanche Center (Salt Lake City)
https://utahavalanchecenter.org/photos
Northwest Weather and Avalanche Center (Washington and Oregon)
http://www.nwac.us/education/resources/