As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) PILOTS REPORTED THAT WHILE CRUISING AT 23 000 FT THEY A HEARD CRACKLING SOUND. SOON AFTER THEY DETECTED THIS SOUND, THE INTERIOR PANE OF THE LEFT WINDSHIELD SHATTERED. HEAT WAS NOT IN USE, AND THE AMBIENT TEMPERATURE WAS -30 C. THE PILOTS IMMEDIATELY REDUCED PRESSURE AND DECENDED TO 10 000 FT, THEN RETURNED TO AMO FOR MAINTENANCE.