On August 29, 1985, 73 firefighters were forced into safety zones, where they took refuge in their fire shelters for 1 to 2 hours while a very severe crown fire burned over them. The incident took place on the Butte Fire on the Salmon National Forest in Idaho. Five firefighters were hospitalized overnight for heat exhaustion, smoke inhalation, and dehydration; the others escaped uninjured. Investigators estimated that without the protection of the escape zones and the fire shelters, at least 60 of the 73 firefighters would have died. Thanks to preparation of safety zones, the effectiveness of the fire shelters, and the sensible behavior of the firefighters themselves, disaster was averted.