On April 7, 2013, two children, a 6 year old girl and a 7 year old boy were playing in a basement in a home that was under construction near their grandparent’s home when a wall collapsed and killed the two children. Firefighters, police and structural engineers attempted to rescue the two children to no avail. The basement had been excavated to a depth of 24 feet and as the children were playing, the dirt walls caved in on them. 75 workers worked throughout the night to reach the children. At 6:00 A.M., the bodies of the 2 children were found. The children’s father had called the police at 6:00 P.M. the night before.
The most potential hazard of excavation of trenches is a “cave in”. Undisturbed soil is kept in place by natural horizontal and vertical forces of surrounding soil. When earth is moved to create an excavation, the natural forces no longer hold back the soil and the trench wall will eventually move downward and inward to cause a “cave in”. Cave-ins occur when the excavation is unprotected and is dug in unstable or previously disturbed soil. Other causes of cave-ins are excessive vibrations from construction equipment or vehicle traffic; a surcharge of load is present near the sides of an excavation (usually heavy equipment); an accumulation of water in the excavation or changes in weather can cause a cave-in (freezing, melting, heavy rains, etc.).
In New York State these excavation sites are governed by Labor Law and OSHA rules and regulations. The excavation safety is The Code of Federal Regulations Part 1926.650-652 (Subpart P), OSHA’s Rules and Regulations for Construction Employment. The standard covers all excavations made below its surface including trenches. These Rules and Regulations define an excavation as any manmade cut cavity, trench or depression in the earth’s surface formed by earth removal. OSHA defines a trench as a narrow excavation made below its’ surface of the ground in which the depth is greater than the width and the width does not exceed 15 feet.
If an excavation is more than 5 feet in depth, there must be a protective system in place while workers are present. An excavation more than 4 feet deep must have a way to get in and out for every 25 feet of horizontal travel (usually a ladder). OSHA requires regardless of the depth of an excavation, “a competent person must inspect conditions at the site on a daily basis and as frequently as necessary during the process of work …”
A protective system must be used if an excavation is 5 feet or greater in depth. Three most commonly used protective systems are: shoring, shielding and sloping. Shoring can be done by timber shores or hydraulic shores that brace against and hold up the walls from collapsing but shields the workers within the structure should a cave-in occur. Sloping refers to the cutting back of the trench walls at an angle so that the walls have little chance of collapse. Sheeting is a type of shoring system that retains the earth in position. Sheeting is used for excavations open for a long period of time. Another type of sheeting, in which plates or shoring grade plywood is used in conjunction with a strutted system, is called an active system. They usually involve aluminum with hydraulic shores which are lightweight and can be reused.
A shield called a trench box is a protective system when continuous horizontal installations are expected. It is placed in the trench and dragged along as work progresses. The top of the shield should extend 18 inches above the level or any materials that could cave or roll into the trench.
Sloping and benching are another means of protecting worker for cave-in hazards. Sloping is a method for excavations in which the walls of an excavation are laid back to an “angle of repose” suitable to the type of soil.
Whenever an excavation occurs, it is most likely a result of the contractors’ failure to use the appropriate protective systems. The 2 children that died in the basement of a home under construction should never have occurred if proper protective systems were used.
If you or a relative has suffered from a construction place accident, call the Law Firm of Dominick J. Robustelli & Associates, PLLC at (914) 288-0800.