What was found
(CAN) THE AIRCRAFT WAS IN CRUISE AT FLIGHT LEVEL 290, APPROXIMATELY 50 MILES NW OF SUDBURY, ONTARIO, ENROUTE FROM THUNDER BAY TO THETFORD MINES, QUEBEC, WHEN THE LT WINDSHIELD INNER PANE SHATTERED. THE CREW REDUCED PRESSURIZATION TO 4 PSI DIFFERENTIAL PRESSURE AS PER FLIGHT MANUAL PROCEDURES AND DIVERTED TO QUEBEC CITY.THE CREW REPORTED THAT THE WINDSHIELD HEAT WAS IN THE "HIGH" SELECTION AND THAT THE OAT WAS -36 DEGREES C AT THE TIME OF THE OCCURRENCE.