Ohia trees are dying rapidly, Why?

[bgiles]

Trees with multiple trunks, sharing roughly the same sun/shade, soil and moisture, exhibit die off on one of the trunks. No trauma has been done to any of my dead ohias; the tree dies with recently healthy leaf appearance. My question: what to do with the wood other than burning. Bury it in cinder? It will break down ultimately. Sure would appreciate some proactive suggestions. Love my ohias, but removing guava and planting koa seem to be the only steps available to keep trees native. Thanks in advance. If only this thread didn't need to keep getting bumped...but there doesn't seem to be a solution yet.