Q.life span of burning bush
What is the lifespan of a burning bush? This summer our burning bush leaves turned all white white and very brittle. There is nothing left and some branches also turned white. Is the bush dead and should I dig it up and replace it now?

Are the white leaves truly white or are they covered in a white substance that makes them look white?
If they have a white substance on them, then this is powdery mildew. It is not normally fatal, but if the case is severe enough it can harm the plant. You can treat the plant with a standard fungicide to take care of this and take steps to improve the airflow through the plant to help keep it away in the future.
If the leaves are turning white themselves, this is typically caused by heat damage. Most commonly, we see it when plants are not properly acclimated when brought from inside to outside. But, less common but still possible is if you have dramatic changes in temps (low to high quickly with several days of high temps) or if the plant is dealing with more intense sun or heat than usual, maybe from a reflection that is focusing the light or an area that is trapping the heat.