A friend of mine was killed when a trench collapsed. Are those kinds of accidents common?

Accidents resulting from collapsing trenches are common. The Occupational Safety and Health Administration (OSHA) reports that at least two workers are killed in collapsing trenches every month, accounting for approximately 24 deaths a year.

The report also revealed the number of trench injuries and deaths in the past five years — 23 in 2016, 11 in 2015 and 11 in 2014. Trench collapses happen without warning and can dump an enormous amount of weight on those inside the trench. Not many people realise that just one cubic yard of soil can weigh up to 3,000 pounds.vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv