There are also many jobs that require entering a confined space, where timely egress is not always possible. Hazards encountered include engulfment (like sand, grain, or marbles), crush zones, and toxic and/or low oxygen atmospheres.
Which brings me to this story here:
5 Dead in Virginia Farming Accident
Sadly, this is a pretty typical scenario. A man is fallen in a pit, overcome by fumes and/or A no/low oxygen atmosphere (you need about a minimum of %18). Someone sees them, goes to down help - they're down now, as well. And so on - 5 in this case, and I believe I've read about as many as 8 or 9 in the past.
Now where I work, the rules are any pit has to be tested by lowering a testing device into the pit to test for ANY atmospheric danger. Additionally, there is usually portable forced-air ventilation there is always one specially trained person (an attendant) OUTSIDE the pit at all times to monitor the situation the entire length of the job. There is also rescue equipment available should the need arise, such as special hoist, lines, self-contained breathing apparatuses (SCBA), etc.ists, .
These dangers are real for pretty much ANY pit or trench, as any gas heavier than air will settle there, poisoning the air, and/or displacing the usable oxygen.
That being said, if you ever see a person down (as in fallen) in a pit or trench, resist your first (natural and understandable) instinct to go down and help them. Call the pro's.
Pretty much the same advice with injured around electrical lines. Call in the people who know.
And final note: if you don't have an air quality tester to lower into a pit, use a hippie. Or a Marxist. Really, any radical leftist type will work, but hippies and radical feminists are the loudest, so you'll know right away if something is amiss.
And never use an emo; they're too quiet, and want to die anyway...