EE WAS IN THE PROCESS OF PICKING UP 100# BAG OF SAND WHEN ACCIDENT OCURRED. 100# BAG HAD FALLEN FROM CONVEYOR BELT TO THE FLOOR. EE BENT DOWN W/VACUUM LIFT IN HIS RIGHT HAND & OTHER UNDER BAG TO GET A BETTER SEAL. HE WAS POSITIONED W/HEAD IN PATH OF VACUUM LIFT HEAD. LIFT SUDDENLY RELEASED IT'S HOLD OF BAG & THE METAL FRAME OF VACUUM LIFT HURLED UPWARDS INTO EE's HEAD.