It depends. if it is police brutality, try and get clear footage of the crime taking place and take it to either the internet or a higher-up. if it is citizen v citizen, then tell either an officer or a fireman, depending on your comfortability.
The workers can be
protected by "trench box". Trench shields which are known as
Trench Boxes or Trench Sheets as well, are steel or aluminum structures
utilized for securing utility laborers while playing out their obligations
inside a trench. They are generally developed with sidewalls of changing
thicknesses held separated by steel or aluminum spreaders.
Answer:
an intense build up of gas and pressure
You did not name the years, so I can not answer it if it is multiple choice
