Injured was carrying rock dust in 23D in crosscut 2-1 at 36.5 block, when a piece of head coal (4' long, 3' wide, 1"" to 8"" thick) fell and struck the employee knocking him to the ground. Miner sustained contusions to the top of his head and some neck pain. No problems with mining machines, methods, training, PPE, or compliance issues.