Cases of cloud-to-ground lightning are classified according to loss of life and property damage. Casualties caused by cloud-to-ground lightning can be subdivided into deaths and injuries. Direct, primary damages from lightning include house and forest fires and facility/building collapses, along with loss of lives. Secondary damages include blackouts, disconnections, traffic accidents, and cessation of operations caused by lightning that strikes plants, communication facilities, traffic facilities, and factories. Cloud-to-ground lightning normally occurs in the summer.