“Probably 80 percent of all projects can be handled with trench boxes,” says Ross. “This is usually the fastest method of placing pipe. When a box can’t be used, then you choose the best alternative, ...

Emergency crews are pictured Nov. 16 at Sallie Barber Road near Breckenridge, where a trench collapse killed 20-year-old Marlon Diaz and partially buried another individual who was rescued.

Prosecutors said Otto, 45, had a history of safety violations and should have installed cave-in protections, known as trench boxes, at the site.