Many people wonder how Forked Lightning hits a water pipe. They think of it as being inside their homes, shielded by brick and concrete. But if the corporate maintenance cover located outside or in the local road is open during a thunderstorm, it is possible that Forked Lightning may hit it, sensing both the metal and the water inside it.
If it does this it will make all of the metal that is attached to it live for a few seconds before it discharges down a local corporate earth rod. It is why the authorities tell the public not to touch anything made of metal inside their homes, or to use sinks and baths, during a thunderstorm.