What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
During a routine taxi out after a large snow/ice event in Saint Louis, the captain notice a slight left engine vibration and thought he might have some ice build up although he was taxiing with anti-ice on. The captain performed an "ice shedding procedure" which is an engine run-up. The vibration increased and the captain elected to return to the gate. Maintenance performed the inspections referenced in the aircraft maintenance manual and discovered multiple fan blades shingled, punctured and scarred on the number 1 (left) engine. The entire fan blade section was removed and replaced. A borescope was conducted with no damage observed to the core engine. Finally, maintenance performed a leak check with the engine at minimum idle and no leaks were noted.
As the FAA filed it
DURING A ROUTINE TAXI OUT AFTER A LARGE SNOW/ICE EVENT IN SAINT LOUIS, THE CAPTAIN NOTICE A SLIGHT LEFT ENGINE VIBRATION AND THOUGHT HE MIGHT HAVE SOME ICE BUILD UP ALTHOUGH HE WAS TAXIING WITH ANTI-ICE ON. THE CAPTAIN PERFORMED AN "ICE SHEDDING PROCEDURE" WHICH IS AN ENGINE RUN-UP. THE VIBRATION INCREASED AND THE CAPTAIN ELECTED TO RETURN TO THE GATE. MAINTENANCE PERFORMED THE INSPECTIONS REFERENCED IN THE AIRCRAFT MAINTENANCE MANUAL AND DISCOVERED MULTIPLE FAN BLADES SHINGLED, PUNCTURED AND SCARRED ON THE NUMBER 1 (LEFT) ENGINE. THE ENTIRE FAN BLADE SECTION WAS REMOVED AND REPLACED. A BORESCOPE WAS CONDUCTED WITH NO DAMAGE OBSERVED TO THE CORE ENGINE. FINALLY, MAINTENANCE PERFORMED A LEAK CHECK WITH THE ENGINE AT MINIMUM IDLE AND NO LEAKS WERE NOTED.