A 2001 EAST MANUFACTURING FRAMLESS DUMP TRUCK'S HYDRAULIC CYLINDER SYSTEM FAILED WHILE THE VEHICLE WAS UNLOADING GRAVEL ON A FLAT CONCRETE PAD. THE FAILURE OF THE CYLINDER OCCURRED AT THE FOURTH CYLINDER, IT BROKE INTO TWO PIECES, CAUSING THE TRAILER TO FAIL ONTO THE TRUCK'S CAB. THE CYLINDER WAS MANUFACTURED BY THE PARKER HANNIFIN CORP. THE INCIDENT CAUSED INJURY TO THE DRIVER AND PROPERTY DAMAGE.