As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SHORTLY AFTER TAKEOFF FROM WHEN THE WING ANTI-ICE WAS TURNED ON, A LOUD POP WAS HEARD FOLLOWED BY A SPIKE IN THE ACFT PRESSURIZATION AND THE LOWER AFTER BODY HEAT LIGHT ILLUMINATED. ACFT DIVERTED AND MADE AN UNSCHEDULED LANDING WITHOUT INCIDENT. MX FOUND THE DUCT CRACKED AND SEPARATED AT THE FLANGE JUST FWD OF THE AFT BULKHEAD. THE DUCT AND CLAMP WERE REPLACED, OP CHECKS PERFORMED, AND THE ACFT RETURNED TO SERVICE.