As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED BLEED TWO FAIL DURING CLIMB. CREW RAN QRH AND REST MESSAGE. DURING FINAL CLIMB FROM FL230 TO 240 CABIN RATE OF CHANGE STARTED RISING 300FPM. CABIN ALTITUDE REACHED 9800FT. CREW DECLARED EMERGENCY AND RETURNED TO DEN. MX PERFORMED OPS CHECK OF PRESSURIZATION SYSTEM AND SYSTEM OPS CHECKED GOOD PER EMB AMM.