This poor tree was certainly beyond the point of repair! You can see very clearly that the heart of the tree is hollow, and therefore dead, meaning that there will be little to no roots anchoring the tree. The upper branches are still living, meaning there is a lot of weight in the upper part of the tree. With no roots, this makes the tree very top heavy and therefore dangerous, as it is likely to fall (and has slowly already begun to do so).
As the wood at the base of the tree is dead, decomposers such as insects and fungi will begin to propagate, eventually breaking the wood down into mulch. This has already started to happen, and here we can see the growth of ganoderma fungi in the folds of the trunk.
Trees in this state must be felled as soon as possible as it is impossible to predict when they might fall.