Struck-By Hazard
Being hit by a moving vehicle, piece of equipment, falling object, or flying material, one of OSHA's "Fatal Four" hazard categories that account for most construction fatalities, alongside falls, electrocutions, and caught-in or caught-between hazards.
Why it matters
Struck-by incidents happen in ways a new worker doesn't always anticipate: a swinging excavator counterweight, material falling from a floor above, a reversing dump truck. Recognizing the specific situations where struck-by risk is highest is a core part of basic jobsite awareness, which is exactly why it anchors entry-level safety orientation.
On a real project
A laborer working near an active excavation stays clear of the excavator's swing radius and the path of trucks backing up to load, rather than assuming a hard hat alone is enough protection from moving equipment.
Who this matters most to
A Safety Manager designs site traffic patterns and spotter procedures specifically to reduce struck-by risk around moving equipment.
Where this goes wrong
A worker walks through an active equipment zone without making eye contact with the operator first, assuming the operator has already seen them. The operator, focused on a different task, doesn't notice the worker step into the machine's path until it's too late to stop.