It may or may not be dead. In the third picture it appears that the tree has recently been raised to expose the root flare. If it has there was root damage involved and might be OK. Scratch the bark on the trunk of the tree. If there is any greenish color the tree is still alive. If it is greenish go get some SuperThrive and follow the directions. It is not a good sign when the leaves die and do not fall off of the tree. From what I can see of the leaves at this time they had some type of fungus or were watered improperly, impossible to say which. But, if this is the case the tree will probably come back in the spring.