According to OSHA, the threats that could lead to severe injury are falls, electrocution, caught-in, and stuck-by hazards. While the first two a relatively self-explanatory, caught-in and struck-by hazards may be a little less clear. Caught-in hazards happen when a construction worker enters a trench or excavation site without the proper protective systems in place-- this mistake can be fatal. Struck-by incidences can occur when the employee is struck by a falling object, moving object, or swinging object. Failure to follow safety protocols around potentially hazardous mechanisms can be fatal, which is why employers and employees must work together to avoid injuries.