Construction Site Safety: OSHA's Fatal Four and How to Prevent Them

The Fatal Four

Every year, OSHA identifies the four leading causes of fatalities in the construction industry. Together, they account for more than 60% of all construction worker deaths:

The fourth category, Caught-In/Between (6.1%), involves workers crushed, caught, or compressed by equipment, materials, or collapsing structures.

Falls: The #1 Killer in Construction

Falls from elevation are the single deadliest hazard in construction, accounting for nearly 4 in 10 construction fatalities. Common fall scenarios include:

• Falls from roofs, scaffolding, and ladders
• Falls through floor openings and skylights
• Falls from unprotected edges and leading edges
• Falls during steel erection

OSHA requirements (29 CFR 1926 Subpart M):

• Fall protection required at 6 feet or more above a lower level in construction
• Acceptable methods: guardrails, safety nets, personal fall arrest systems
• All floor holes and wall openings must be covered or guarded
• Workers must be trained on fall hazards and protection systems

Struck-By Hazards

Workers hit by falling, flying, swinging, or rolling objects. Common scenarios:

• Materials falling from overhead work
• Workers struck by vehicles on active job sites
• Tools or debris ejected from power equipment
• Loads swinging from cranes or rigging

Prevention essentials:

• Hard hats required in all areas with overhead hazards
• High-visibility vests for workers near vehicle traffic
• Secure all tools and materials at elevation
• Establish exclusion zones under crane operations

Electrocution

Contact with live electrical sources, particularly overhead power lines, exposed wiring, and damaged electrical equipment:

• Maintain minimum 10-foot clearance from overhead power lines (higher for higher voltages)
• Use GFCI protection on all temporary power
• Inspect all cords and equipment daily
• Lock out/tag out all electrical systems before work
• Only qualified electricians should work on electrical systems

Caught-In/Between

Workers caught, crushed, or compressed between objects:

• Trench and excavation collapses (cave-ins)
• Workers caught in unguarded machinery
• Compressed between vehicles and fixed objects
• Structural collapses

OSHA requires trench protection (sloping, shoring, or shielding) for all excavations 5 feet or deeper. A competent person must inspect trenches daily.

Building Reporting Culture on Job Sites

Construction sites present unique reporting challenges:

• Transient workforce. Workers move between sites and employers, reducing connection to any single safety program.
• Multiple contractors. Hazards created by one subcontractor may endanger another's workers, but reporting across company lines is rare.
• Production pressure. Tight schedules and weather constraints create pressure to cut safety corners.
• Language barriers. Multi-language workforces need reporting tools available in their native language.
• Fear of job loss. Day laborers and subcontracted workers have even less job security than permanent employees.

Effective safety reporting in construction requires anonymous, mobile, multi-language tools that workers can access on their personal phones without identifying themselves to any employer on the site.