What killed RadioShack?

Could you elaborate on the factors that ultimately led to the downfall of RadioShack? Was it a gradual decline due to changing consumer preferences and the rise of online retail, or was there a specific event or series of events that triggered its demise? How did the company's management and strategic decisions contribute to its struggles, and what could they have done differently to prevent this outcome? Additionally, what lessons can be learned from RadioShack's failure that can be applied to other businesses in the retail and technology sectors?