As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PIT - FLT 274 - EN ROUTE LGA-SDF, CREW RECEIVED THREE CHIME WARNING FROM THE MFDU AND NOTED THAT THE CABIN ALTITUDE WAS CLIMBING THROUGH 10,000 FT. CREW PERFORMED AN EMERGENCY DESCENT. THE FLIGHT DIVERTED TO PIT AND LANDED WITH NO FURTHER INCIDENT. (M)