Dec. 4—BLUEFIELD — Soft and wet ground caused a septic truck to slide and then flip on top of a man on Tabor Road, according to new details Monday from the Mercer County Sheriff's Department.

It was a scene that not even many rescue workers can say they’ve come across before: A crumpled RV atop an overturned septic truck, and a third mangled car that was being towed. The truck’s ...