As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN)DURING PRE-FLIGHT, PILOT CYCLED THE FUEL SHUT OFF SYSTEM AND NOTICED A DIFFERENT NOISE THAN NORMAL. FUEL VALVE ACCESS PANEL REMOVED AND PAN AREA WAS FOUND 2/3RDS FULL OF ICE WHICH HAD TOTALLY ENCASED THE FUEL SHUT OFF VALVE. THE PAN DRAIN WAS CLOGGED WHICH ALLOWED WATER TO BACK UP DURING SEVERE RAIN STORM THE PREVIOUS NIGHT AND DUE TO A DRASTIC TEMPERATURE CHANGE BECAME ICE.