Incident date: 2016-08-09
NAICS industry code: 238110

An employee entered a trench that was properly shored with a steel trench box and access ladder. The employee was using a cut off saw to cut through an abandoned water main. The section of main was isolated/shut off and restrained from the live portion of the main the prior day. The employee successfully cut through the main and turned around to place the cut off saw on 
the ground. As he did, the water main valve from the live portion of the 
main failed and separated from the pipe striking his knee. Water from the main began to fill the trench. As the employee began to exit the trench box his hard hat fell off. The employee fell and his head hit the spreader bar. The employee suffered a left knee fracture and a head contusion.

Hazard classification:
code_event: title: Struck by dislodged flying object, particle
code_source: title: Valves, nozzles
code_nature: title: Fractures
code_body: title: Knee(s)
severity: moderate