What was found
FLT NR 423 - ELP - THE NR 1 ENG FAILED WITH AN ENGINE FIRE WARNING INDICATION WHILE EN ROUTE FROM IAH TO LAX. THE FAILURE WAS ACCOMPANIED BY VIBRATION AND LOSS OF THE LEFT HYDRAULIC SYSTEM. THE NR 1 ENGINE WAS SHUT DOWN AND THE AIRCRAFT WAS DIVERTED TO ELP WHERE IT LANDED WITHOUT INCIDENT. THE NR 1 ENGINE WAS REMOVED AND REPLACED. INVESTIGATION REVEALED THAT THE PRIMARY CAUSE OF ENGINE FAILURE WAS DUE TO THE LIBERATION OF A STAGE 1 BLADE WHICH BROKE ONE INCH BELOW MID-SPAN. THE BLADE FAILURE WAS CAUSED BY FOD. SUBMITTER STATES 'BLUE ICE WAS SUSPECTED'.