In my book, five middle-school students are stranded in a desert when their small plane crashes. The pilot dies saving one of them, and there is no civilization within hundreds of miles. How long should it take them to realize that there's no way out, and become determined to survive?
Five students, five different characters. Probably five different lengths of time to become aware of the seriousness of the situation. Some of them might never get there.
There might be a time when they all reach a collective interpretation, but the interesting writing (and reading) is going to be the conflict in views leading up to this.