Although lightning itself can’t hit you, the electricity produced by a lightning strike can travel through conductive surfaces such as wires and pipes within your house. If you happen to be touching one of theses wires or pipes (think telephone or shower) you can be electrocuted. Lightning is a master of trickery and can do some pretty strange things. Just remember though, the odds of you being killed by lightning inside a building during a thunderstorm are considerably worse than winning the Powerball lottery.
Lightning has no mass and defies the laws of gravity. It will zig-zag all over the place by going up, down, sideways, forwards and backwards. It travels great distances, sometimes as much as 70 miles! Adding to its mystique, lightning will travel along the path of least resistance, which can span hundreds of feet along conductive surfaces not quite visible to you or I. Why is this important?
Think about what runs into and all around the inside of your house. There are conductive copper pipes bringing the water into your house from outside. There are solid gauge copper wires leading to every wall outlet, light switch, and electrical appliance in your house that attach to a very tall utility pole or one of those large green boxes somewhere on your street. There are copper telephone wires running to every phone jack, again from a utility pole or some other metal box on your street. There are copper coaxial cables running from your satellite dish or cable TV provider. All of these things conduct electricity and start outside your house.
Let us suppose a lightning strike hits a utility pole down the street from your house, or tree right out front. The lightning quickly follows the path of least resistance, which by the way, we have no way of knowing and may not be obvious, but we do know copper wires and copper pipes are conductive. As the electricity races down the wires, it arcs onto the telephone wires which run into your house. If the grounding system on you telephone wires is broken or not adequate, the electric current from the lightning strike can make it to the person on the other end of the phone. In addition to outdoor fatalities caused by lightning, a number of people are injured indoors every year, including individuals who are using the telephone during a thunderstorm.
What about copper pipes? If copper is conductive (water as well), can the electricity from a lightning strike get to you if you’re taking a shower, a bath or sitting on the toilet? I suppose it’s possible, but you have to remember, your city water pipe coming into the house is buried underground. This means the electricity from a lightning strike will dissipate into the earth instead of traveling down the pipes. Finally, drain pipes in houses are usually made of PVC (or plastic) which is not conductive, so you don’t need to worry about sitting on the toilet in a thunderstorm.
Remember how we have no way of knowing what the path of least resistance is? Remember how lightning is a master of trickery? While I lived in North Carolina, the homeowners right behind us had their house hit by lightning. It went right through the top of their wooden roof creating a 2×2 foot hole. It must of flashed to the electrical wiring in the attic because it blew up every electrical appliance plugged into a wall outlet. The internal wiring inside the walls vaporized, blowing out chunks of drywall and left black acrid scorch marks in their place. About 35 feet from the front of their house was a utility pole and their house was surrounded by 60 foot pine trees. That day, the path of least resistance didn’t include any of those taller objects, but instead was an asphalt shingle roof. Here is a link to some pictures of another house unlucky enough to be struck by lightning.
One could drive themselves crazy worrying about stuff like this. Just remember, the safest place to be during a thunderstorm is in your house and the odds of being struck by lightning are far worse than winning the Powerball lottery. If you happen to live in a part of the country that experiences a lot of thunderstorms, a good investment might be some sort of lightning protection device such as a properly grounded lightning rod or surge arrestor. However, simply staying off the phone and not taking a shower during a thunderstorm would be an even better idea.