In January 2003, two construction laborers somewhere in the U.S. died when the trench in which they were working caved in. Only teenagers, the brothers were laying conduit in the trench – which was eight feet deep and only two feet wide – when the walls collapsed over them, according to an incident report by the National Institute of Occupational Safety and Health (NIOSH).

The young workers had no business being in that unshored trench. But with the pressure on to get work done faster, or due to carelessness, more experienced workers also take chances with trench safety every day.

An opportunity to remind workers about the importance of safety in the trenches came in a report released on April 23 by the Centers for Disease Control and Prevention, based on data from NIOSH. The data showed that 542 U.S. construction workers were killed during construction and excavation accidents between 1992 and 2001. Three-quarters of the deaths were caused by cave-ins, and construction laborers comprised more than 75 percent of the fatalities.

Excavation fatalities don’t appear among the top three killers of construction workers. However, MIOSHA Construction Safety and Health Division Manager Rick Mee said excavation fatalities are “disproportionately high,” given the relatively low number of construction workers who toil in ditches.

“Accidents in trenching can be anticipated and prevented,” Mee said. “Certainly complacency and carelessness on the part of workers is one factor. But as construction projects get more complex, better training for workers becomes more important, and training can be expensive, but it’s very important. Contractors must commit to including the cost of safety and health training for their workers into their business.”

Said Jerry Faber, a former MIOSHA construction safety inspector and now director of safety for the Associated General Contractors, Greater Detroit Chapter: “Sometimes people get lazy, or they’re in a hurry or they’re pressured and they don’t follow the rules and do it right. Accidents happen when people cut corners, and you can’t do that working in a trench.”

Michigan averaged two excavation fatalities per year from 1992 to 2001, according to MIOSHA, and another two workers were killed in trench accidents in 2003. In the U.S. during that period, annual excavation fatalities ranged from a low of 44 in 1993 to a high of 65 in 1996, for an overall average of 54 deaths per year.

Following are some issues to consider when it comes to trenching, according to the OSHA excavation standard and the Center to Protect Workers’ Rights (the safety arm of the AFL-CIO Building Trades Department):

• A competent person must be designated by the employer to conduct daily inspections of excavations, and take appropriate measurers necessary to protect workers. Trench hazards can increase at any time after rainstorms or even as a result of heavy equipment vibrations.
• Workers must have a way to get out, such as a ladder, if a trench is more than four feet deep.
• The contractor must have all utilities marked before digging.
• Use adequate protective systems (such as shoring, shields and trench boxes) or sloping or benching of the sides of excavations as protection from cave-ins.
• The spoil pile must be kept two feet or more from the edge of the trench.

“Cave-ins are perhaps the most feared trenching hazard,” OSHA said, “but other potentially fatal hazards exist, including asphyxiation due to lack of oxygen in a confined space, inhalation of toxic fumes, drowning, etc. Electrocution or explosions can occur when workers contact underground utilities.”