I need to replace a faulty breaker. Here's a picture of my main breaker box. There's no master switch that I can see that shuts off power to all of the breakers.
Following the line up and out of the box, it runs along the basement ceiling and out through a hole in the foundation.
Let me know if you need to see something else.
Edit. Resolved! I found a master switch on the outside of the house in a panel adjacent to the meter. Weird that anyone can just walk up to my house and turn all of the power off.
If you don't need to turn the power back on, you can turn off all the power by throwing a gallon or two of water at it.