As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BOS - FLT 1204 - EN ROUTE PHL-PWM, THE OUTER PANE OF THE CAPTAIN'S WINDSHIELD BEGAN TO ARC AND CRACK. FLIGHT DIVERTED TO BOS AND LANDED WITH NO FURTHER INCIDENT. MAINTENANCE REPLACED THE WINDSHIELD AND THE WINDSHIELD HEAT CONTROLLER. (X)