As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 620 HOU-BOS, AIR RETURN TO HOU DUE TO ENG 1 BLEED LEAK AT FL190 IN CLIMB. LEVELED RAN QRH AT 250 RESET DID NOT WORK. STARTED APU, APU NORMAL BUT NO BLEED AIR FROM ANY SYSTEM. CAB ALT REACHED 11600 PRIOR TO EMERGENCY DESCENT. T/S BLEED 1 LEAK FOUND BAD PRECOOLER. REMOVED AND REPLACED ENGINE 1 PRECOOLER IAW 36-11-08-04. OPS AND LEAK CHECK GOOD. NOTE: ENGINE 2 BLEED ALREADY ON MEL.