You should never stand behind a table saw blade when cutting wood. The reason: “kickback,” the term for when the ultra-fast-spinning blade grabs the wood, lifts it up and throws it back away from the saw.
Woodworker David Picciuto discovered the power of this effect firsthand during a trip to KenCraft woodworking supply store in Toledo, Ohio. A kickback incident there drove a flying board into a wall, where it dented the sheet metal on the other side. The wood remained in the wall as a warning during Picciuto’s visit.