I live in a wooded housing development that is about 4 years old. It was a fully wooded area before construction. Almost all Maple and Ironwood trees. They tried to save as many of the fully mature Maples as possible. Every mature tree that was left in a front yard has since died. I assume far too much disturbance of the roots with driveways, biulding equipment, etc. Now we are seeing or have been seeing several other large Maples beginning to die away. They all start by losing the leaves at the top or end of the branches and it spreads from there. It's worse each year. These are 80+ foot Maples 2+ foot diameter trunks. Some of them are 40 feet away from any structure and still surrounded by smaller trees so I don't think the root base was affected. What is causing these to slowly die and can anything be done to save them? I just noticed the first bare branch on one of mine this year.

Thanks,