As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 721, CLT-CUN: DURING CLIMB, LEFT HYDRAULIC SYSTEM DECREASED TO ZERO WITH ASSOCIATED HYDRAULIC RESERVOIR LIGHT ILLUMINATED. FLIGHT RETURNED TO CLT. MAINTENANCE FOUND THE PRESSURE LINE CHAFED THROUGH FROM CONTACT WITH COWL HOLD-OPEN ROD PIVOT. REPLACED LINE, AND REPOSITIONED TO AVOID FURTHER CONTACT. LEFT ENGINE DRIVEN HYDRAULIC PUMP ALSO REPLACED.