https://www.youtube.com/watch?v=pL9q2lOZ1Fw

Don't let the sensationalist headline 'WATCH HOW HACKERS BREAK INTO THE US POWER GRID' fool ya. This is actually a well made short video (15 mins) that gives an overview of a red team doing physical penetration testing against a US power grid company.

Gives nice glimpses into the tools, tactics and procedures used by professionals attacking a site. My favorite part was when they couldn't pick a fence's locks, they just unscrewed the bolts and opened the fence next to the locks. Do the simplest thing that works. Pure and simple.