Anything mounted on top of a building must be considered for lightning protection. These light posts, for example, rise above the parking structure and had to be connected to the facility’s lightning protection system. Air terminals are mounted at the top of the light posts, and cables visible at the base of the posts connect to the lightning protection grounding system. Cables are not required between the top and bottom of the light posts because the metal tubes are thick enough to act as their own lightning conductor. The dramatic clouds, seen at sunset, are left over from a thunderstorm that passed through the O’hare International Airport, Chicago, earlier in the day.