Here is a story from an unknown traditional source.
 
One day, one of the young children of the tribe was walking in the forest and found a young deer that had been hurt. He tried to help it and he put herb and rain water and tried to make the deer well, but it was too late.
 
The deer said, "I must go now, it is my time. But remember, I shall not be gone forever. Life in the forest lasts all the time. I shall return someday."
 
With that, he closed his eyes, and the young child cried very much, for he had lost a friend.
 
The Great Spirit was watching this and said, "There is so much love in that child. We should save that love to remind others that life is precious to everyone."
 
And the Great Spirit picked up all of the tears that the child had cried and put them into the sky, and they became stars.
 
So when you look at the stars, remember my friends, those were tears for a life that had been taken at one time. They are to remind you that life is precious.