In the twenty first century the safety and health of the construction industry has significantly improved. This improvement can be attributed to a number of issues, including increased training focus of employees/employers, greater knowledge of safety professionals, increased oversight by insurance companies, and focused inspections by the Occupational Safety and Health Administration (OSHA). An excavation is defined as any man-made cut, cavity, trench, or depression in the earth's surface. The hazards associated with an excavation are numerous and include weight, vibration, underground utilities, water, and soil erosion. The choices of protective systems include sloping and benching, shoring, and shield systems. Shields are manufactured by a number of companies and are designed to protect workers working within the confines of the shields. There are four main types of electrical injuries, categorized as either direct or indirect injury. They are electrocution or death because of electrical shock, electrical shock, burns, and falls.