What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
The pilot filed an IFR flight plan from klns to kmrb in order to practice the RNAV 26 approach.
After landing at 21:13 (EDT, according to the foreflight track log), the pilot taxied half way down runway 26 to taxiway b, crossing taxiway e and onto the apron outside mrb aviation, the local FBO.
Both the FBO was closed, and the kmrb tower, the pilot parked on the apron without shutting off the engine.
Prior to taxiing, the pilot re-lit the runway and taxi lights using the CTAF frequency. Completed his normal taxi checklist to turn on the taxi lights, check for obstacles, release the parking brake, and then proceed with 1000 rpms. After he proceeded to taxi, the propeller and engine both stopped, as did the forward motion of the airplane. The pilot ran the airplane into a ditch and ground the propeller causing a prop strike.
As the FAA filed it
THE PILOT FILED AN IFR FLIGHT PLAN FROM KLNS TO KMRB IN ORDER TO PRACTICE THE RNAV 26 APPROACH.
AFTER LANDING AT 21:13 (EDT, ACCORDING TO THE FOREFLIGHT TRACK LOG), THE PILOT TAXIED HALF WAY DOWN RUNWAY 26 TO TAXIWAY B, CROSSING TAXIWAY E AND ONTO THE APRON OUTSIDE MRB AVIATION, THE LOCAL FBO.
BOTH THE FBO WAS CLOSED, AND THE KMRB TOWER, THE PILOT PARKED ON THE APRON WITHOUT SHUTTING OFF THE ENGINE.
PRIOR TO TAXIING, THE PILOT RE-LIT THE RUNWAY AND TAXI LIGHTS USING THE CTAF FREQUENCY. COMPLETED HIS NORMAL TAXI CHECKLIST TO TURN ON THE TAXI LIGHTS, CHECK FOR OBSTACLES, RELEASE THE PARKING BRAKE, AND THEN PROCEED WITH 1000 RPMS. AFTER HE PROCEEDED TO TAXI, THE PROPELLER AND ENGINE BOTH STOPPED, AS DID THE FORWARD MOTION OF THE AIRPLANE. THE PILOT RAN THE AIRPLANE INTO A DITCH AND GROUND THE PROPELLER CAUSING A PROP STRIKE.