As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING CLIMB OUT WHEN PASSING THROUGH FL230, THE PILOT NOTED ZERO READING ON OIL PRESSURE INDICATOR ON NR 1 ENGINE. THE PILOT ELECTED TO SHUTDOWN THE ENGINE AND RETURN TO ORIGINAL AIRPORT WHERE AN UNEVENTFUL LANDING WAS PERFORMED. TROUBLESHOOTING IS IN PROGRESS.