A Confined Space

A confined space tends to be an arch nemesis to contractors and construction employees. The incident I will refer to for this question deals quite directly with the hazards of confined spaces.
The Human factor theory of accident causation attributes accidents to a chain of events ultimately caused by human error, this is the case especially when it comes to confined space entry. The systems theory models are the person, the machine, environment and information; risks; and the task to be performed.
The day of the accident started off like most others the contractor and his crew talking about the day ahead and what they were to accomplish that day. The crew consisted of the foreman, a machine operator and a laborer on his second day of work with the company. They were going to dig a four-foot trench around the front of a home in a residential neighbor hood. The trench would be four to five feet deep and inside the trench they would put drainage tile to try to stop the flood of water in the homes basement. The contractor was new to the area and was not aware of the soil consistency in the area, which was very sandy and unstable. They began digging with no plan in place as to where they would pile the dirt, so they piled the dirt close to the hole as possible to help when they had to re-fill the hole with the dirt they had removed. Again they were not planning. They finished the digging ahead of schedule, the construction foreman then left the site with one of the other workers to go to the local coffee shop to get a hot cup of coffee for everyone, the problem being he left the only other employee at the job site. While his boss was away, the laborer on-site was instructed to clean the edge along the basement wall and wait for the dump truck with the crushed stone to arrive.
The dump truck arrived shortly after the foreman left, the laborer wanting to impress his boss, had the truck back up to the house and dump the load as close to the house as