Trench collapses,cave-ins and sidewall collapses are perhaps the most feared hazards in the trenching and excavating industry. But other potentially fatal excavation dangers exist, including asphyxiation due to lack of oxygen in a confined space, inhalation of toxic fumes, suffocation from the crushing weight of soil on the buried worker, falls and drowning. Electrocution or explosions can also occur when workers contact underground utilities.OSHA requires that workers in trenches and excavations be protected and that safety and health programs address the variety of hazards they face. Excavation cave-ins are a major source of fatalities within the construction industry. Trenching accidents on U.S. construction sites account for an estimated 100 fatalities per year, with at least 11 times as many workers injured.
EXCAVATION INJURIES & DEATHS
Workers in trenches, excavations, and other restricted spaces are presented with the high risk of cave in accidents, falls, wall collapse, risks of oxygen depletion, toxic fumes, and water accumulation. Trench wall protective systems or boxes help protect workers while working in trenches or excavations. When a side wall collapses or the trench caves in, the worker down in the trench can receive serious personal injuries or die from being crushed by the soil or ground from the cave-in, die from asphyxia from lack of oxygen, suffocation, be seriously injured from falls into the trench, be injured from falling debris, receive serious or fatal injuries from being struck by trenching equipment or backhoes operating in or nearby the trench or hole being excavated and die from poisonous fumes and gases in the trench itself.
TRENCH AND EXCAVATION CAVE IN ACCIDENTS PREVENTION
- READ, UNDERSTAND & APPLY APPLICABLE SAFETY RULES FOUND IN 29 CFR 1926.652
- Evaluate soil conditions and select appropriate protective systems;
- Use retaining devices, such as a trench box, that will extend above the top of the trench to prevent equipment and spoils from falling back into the excavation;
- Where the site does not permit a 2-foot setback, spoils may need to be temporarily hauled to another location;
- Have a qualified and competent person trained in trench safety with authority to remove workers from excavation immediately or shut down job site if conditions warrant;
- Construct protective systems in accordance with the standard requirements;
- Preplan; contact utilities (gas, electric) to locate underground lines, plan for traffic control if necessary, determine proximity to structures that could affect the choice of the protective system.
- Test for low oxygen, hazardous fumes, and toxic gases, especially when gasoline engine-driven equipment is running, or the dirt has been contaminated by leaking lines or storage tanks.
- Ensure adequate ventilation or respiratory protection if necessary;
- Provide safe access into and out of the excavation;
- Provide appropriate protection if water accumulation is a problem;
- Inspect the site daily at the start of each shift, following a rainstorm, or after any other hazard-increasing event;
- Keep excavations open the minimum amount of time needed to complete operations;
- Protect employees from loose rock or soil;
- Place spoils, materials, and equipment set back a minimum of 2′ from the edge of excavation;
- Place barriers, fences or barricades at all excavations, wells, pits, shafts, etc;
- Erect walkways and bridges over excavations 6′ or more in-depth and equip them with guardrails;
- Prohibit employees from working or walking under suspended loads;
- Prohibit employees from working on faces of sloped or benched excavations above other employees;
- Require all employees in trenches to wear hard hats;
- When employees enter deep confined excavation they must wear a safety harness and lifelines;
- Employees trained in the use of Personal Protective and Emergency Response Equipment;
- Keep excavations open the minimum amount of time needed to complete operations;
- Precautions must be taken to prevent accumulation of water and the dangers to trench workers;
- Inspect the site daily at the start of each shift, following a rainstorm or snowstorm, or after any other hazard-increasing event
- Testing conducted to ensure that the atmosphere remains safe to breathe and non-explosive and/or
- Utility companies contacted and/or utilities located, marked and protected from contact with excavators and backhoe equipment.
ACTUAL TRENCH ACCIDENT CASES
LOOSE SANDY SOIL TRENCH CAVE IN ACCIDENT– An employee was in a trench installing forms for concrete footers when it caved-in, causing fatal injuries. The trench, which was 7 1/2 feet deep, was in loose, sandy (Type C) soil, and no inspection was conducted prior to the start of the shift.
RETAINING WALL (TRENCH WALL) COLLAPSES – A 27-year old male laborer (victim) died after being trapped in soil over his head as a result of a trench that caved-in. The victim was buried in soil over his head. The coroner’s report stated the cause of death to be asphyxia. The victim was digging out the bottom of the trench in order to expose an existing drain pipe. On one side of the trench was a retaining wall and the other side was a dirt wall which was part of a hillside. He and another laborer were piling the dirt on the hillside above the east wall of the trench. Later the other laborer pulled up buckets filled by the decedent with the spoils placing them on the hillside above the trench wall as well as on the south side of the excavation. The trench wall that collapsed was not shored or otherwise protected from earth movement. The soil had been previously disturbed in the area of the trench. There was no competent person to check the soil and excavation at the site and no initial hazard assessment was performed. The victim received no training from the company for whom he worked.
9 FOOT DEEP TRENCH WALL COLLAPSE KILLS WORKER – Two employees were installing 6″ PVC pipe in a trench 40′ long x 9′ deep x 2′ wide. No means of protection was provided in the vertical wall trench. A cave-in occurred, fatally injuring one employee and causing serious facial injuries to the other.
UNPROTECTED TRENCH WALL COLLAPSE– An inadequately protected trench wall collapsed, killing one employee who had just gotten into the trench to check grade for installation of an 8″ sewer line. The trench was 20-25 feet deep and had been benched about one bucket-width (4 feet) on each side. At the time of the collapse, a backhoe was still extracting soil from the trench.
INADEQUATE SHORING OR TRENCH PROTECTION DEVISE USED -Four employees were in an excavation 32′ long x 7′ deep x 9′ wide boring a hole under a road. Eight-foot steel plates used as shoring were placed against the sidewalls of the excavation at about 30-degree angles. No horizontal bracing was used. One of the plates tipped over, crushing an employee
WORKER IN TRENCH DIES FROM FUMES – In a trench, 6 feet deep x 32 inches wide, an employee was applying a waterproofing primer containing methyl chloroform and 1,4-dioxane to the foundation of a house. The employee was overcome by the fumes and later died of trichloroethane intoxication. No one had tested the atmosphere in the trench, the employees were not provided with respiratory protection, and mechanical ventilation was not used.
TRENCH WALL CAVE- IN -Two employees were laying pipe in a trench 12-feet deep when one of the employees saw the bottom face of the trench move. He jumped out of the way along the length of the trench; the other employee was fatally injured as the wall caved-in. The walls of the trench were not sloped, and no means of emergency egress were provided.
TRENCH NOT SHORED OR SLOPED – In a 15-foot deep trench, which was not shored or sloped properly, two workers were laying sewer pipe. The only means of egress was by climbing the backfill. While exiting the trench, one of the workers was trapped by a small cave-in. The second employee tried to extricate him, but a second cave-in occurred, trapping the second employee at the waist. The second cave-in actually caused the death of the first employee; the second employee sustained a hip injury.
TRENCH ACCIDENTS, CAVE IN & WALL COLLAPSE LAWSUITS
If you or a loved one have suffered a serious injury or accidental death as a result of a trench wall/excavation cave-in or retaining wall collapse or any other serious injury resulting from unsafe trenching practices, then you may have a right to file a lawsuit case against the negligent parties and companies involved. Call now and get your questions answered. Talk to a Board Certified Personal Injury Trial Lawyer FREE CONFIDENTIAL CONSULTATION at (713) 529-9377.