As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DIVERTED, ACFT WAS GNDED. YELLOW HYD SYS FAILURE AT CRUISE WITH HEAVY SMOKE IN CABIN. YELLOW SYS LO PRESS FOLLOWED BY LOW FLUID LEVEL. CREW DEPLOYED OXYGEN MASKS, DECLARED AN EMER & DIVERTED WHERE THE ACFT LANDED SAFELY WITH NO FURTHER INCIDENT & TAXIED TO THE GATE. FOUND HYD FLEX LINE 3096GM LEAKING IN THE AFT CARGO COMPARTMENT CEILING AREA, FWD OF THE CARGO DOOR WHICH WAS REPAIRED IAW AMM 20-23-11-00-300. A SATISFACTORY LEAK CHECK WAS ACCOMPLISHED.