Working on an oil rig in the North Sea has its frustrations, its problems, and its dangers. In July of 1988, employees on the Piper Alpha platform were looking forward to having to work around construction as problem areas in the rig were updated - paint to be applied, sprinkler heads to be unclogged, and a broken safety valve to be fixed and replaced. In the end, a series of lapses and mistakes would lead to the deadliest oil rig disaster in history.

In most cases, we can trust the ground beneath our feet. We expect it to be solid, to hold firm, and to not move when we stand on it. Some places we can expect earthquakes, but most of the time we don't expect to look out the window and see the very land we've gotten used to outside every day slamming down toward our homes.

When someone says a mass shooter was "going postal," the term goes back to a series of workplace shootings in the United States postal service going back to the mid-1980s. The deadliest of those took place in Edmond, Oklahoma, when an unsettling middle-aged man walked into work on August 20, 1986, with three guns in his mailbag.