Trees get sick and develop problems that endanger their survival. They are no different from other living organisms.
Trees also coexist with humans and a threat to a tree can also pose a danger to humans.
People can be killed or injured by falling branches or worse falling trees. That is why it is so important for people to know basic signs a tree will exhibit when it is having troubles. Trees usually show signs when they are sick just like humans. The signs might be extremely obvious like dying branches or bark falling away from the trunk. These two signs are sure indicators that something is happening to the tree.