Did you ever get a shock when you closed your car door? That shock was caused by static electricity. Static electricity can give people a shock, but it is harmless. Lightning, however, is a dangerous form of electricity. It can kill people. Lightning can also start fires in grasslands and forests and damage buildings. We can protect a building from lightning by putting a thin piece of metal on top of it. We call this piece of metal a lightning rod. It is usually about thirty centimeter long. The lightning hits the rod and then travels down a heavy wire to another piece of metal in the ground. In this way, the lightning does not damage the building. It goes into the ground instead. Lightning usually hits the tallest building in an area. The Empire State Building is one of the tallest buildings in New York. Lightning hits it an average of twenty-three times a year!