A Low RPM shut down is usually the point at which the ECU gave up the fight to keep the engine running. Covers a multitude of sins, particularly when no other specific reason can be given, most often the result of air in the fuel lines or no fuel reaching the engine.

Need more of the story to go any further: in the air, on the ground, white smoke trail or not, visible air in the lines, UAT empty, throttle setting, etc., are all clues.