Picture a new residential tower going up in Mott Haven or along the Grand Concourse. You're a laborer carrying material across the sixth floor, moving fast because the pour is behind schedule. The plywood cover over the elevator hoistway — the vertical shaft where the elevator will eventually run — was pulled off that morning so the elevator subcontractor could take measurements, and nobody put it back. One step in the wrong place and you drop two stories into a concrete pit.

Somewhere in Queens right now — a sewer tie-in in Jamaica, a water service line in Flushing, a foundation excavation for new housing in Maspeth — a worker is standing at the bottom of a trench with nothing holding the walls back. A trench collapse takes seconds. The walls let go, and tons of soil bury a man where he stands, often close enough for his coworkers to hear him. If your family just got that phone call, you need to understand two things quickly: a trench collapse is