There are a lot of different factors that can influence the direction a tree falls when it is cut down. The angle at which the tree is growing, the direction from which the person cutting down the tree is cutting it, the weight of the branches on one side versus the other side of the tree and even the strength of the wind can cause a tree to fall in a different direction than what the person cutting it down is anticipating. When this happens, trees can land on people, roadways, electrical poles, vehicles and homes, causing a significant amount of damage and even death.
Falling trees can damage power lines if they come into contact with them while being cut down. If a tree hits a power line, there is a risk of electrocution and a fire may be started.