An employee was grading lumber in the planer mill (dry end) when a lumber plank "crossed-up" and slowed/stopped production. When the employee tried to clear the "crossed-up" lumber plank, his left hand was crushed by the plank and a u-shaped piece of steel lacerated his left hand between the wrist, thumb, and first finger. He suffered a partial de-gloving and a broken bone in the thumb.