As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED A BLEED SYSTEM 2 LEAK MESSAGE AFTER TAKEOFF. THE AIRCRAFT RETURNED TO STL AND LANDED WITHOUT INCIDENT. MAINTENANCE INSPECTED THE BLEED SYSTEM AND FOUND THE Y-DUCT IN THE NR 2 PYLON CRACKED. THE Y-DUCT WAS REPLACED WITH NO FURTHER DEFECTS NOTED.