What was found
(CAN) AFTER PARKING, IAW INTERNAL PROCEDURE, F/O PULL RT WATER DUMP EMERGENCY CONTROL HANDLE TO EMPTY WATER TANKS. AS SOON AS HE RELEASED THE HANDLE, THE LT WATER DUMP CONTROL HANDLE ASSY, PN 215-93838-820, BROKE-OUT ALL ALONG THE WELDED AREA. NOBODY TOUCHED THE LT HANDLE BECAUSE THE CAPTAIN WAS ENDING THE TAXIING PROCEDURE, 1 HAND ON THE STEERING AND THE OTHER ON THE ENGINE CONTROL LEVER.