Answer: Unfortunately, this really does not sound good at all. You might want to consult with your local county extension to see if you can get a specific diagnosis of what happened, in case it is caused by something that could affect additional plants in your landscape. In the meantime I suspect it may have been rootbound below ground and summer heat/drought stress has finally caught up to it, but that is just a guess. There are numerous pests and diseases that could cause browning. I'm sorry I can't be more specific for you and I'm really sorry about your Tanyoso Pine.
Q&A Library Searching Tips