Complex sentence: The avalanche attracted a high level of media attention because of the high level of experience and notoriety of all of sixteen people on the trip and snowboarders involved and because several of them were members of the freeskiing media, including reporters and a photographer from Powder Magazine.
Split into simpler sentences: The avalanche attracted a high level of media attention because of the high level of experience and notoriety of all sixteen skiers and snowboarders on the trip. Participants included professional competitive skiers and members of the freeskiing media, including reporters and a photographer from Powder Magazine.