What does this incident tell you about maintaining and increasing brand value over time?

Answer the following question about Michael Phelps based on the knowledge of chapter 1 of the textbook:
Following the Beijing Olympics, a photo published by a British tabloid showed Michael Phelps using a “bong,” a device for smoking marijuana, at a party in South Carolina. Kellogg’s withdrew Phelps’s endorsement contract. What does this incident tell you about maintaining and increasing brand value over time?