As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAH FLIGHT 3972, THE CREW REPORTED HYDRAULIC 1 LO QUANTITY IN FLIGHT WITH QUANTITY AND PRESSURE DROPPED TO ZERO. THE AIRCRAFT LANDED IN IAH WITHOUT INCIDENT. MAINTENANCE INSPECTED THE AIRCRAFT AND FOUND THE LEFT HAND ENGINE HYDRAULIC PRESSURE LINE TO BE SPLIT. THE SUBJECT LINE WAS REMOVED AND REPLACED, OPERATIONAL AND LEAK CHECKS COMPLIED WITH SATISFACTORILY, AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.