As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EN ROUTE FROM BNA TO MSP RECEIVED HYD NR 1 LOW PSI MSG, PRESSURE AND QTY WENT TO ZERO. EMERGENCY DECLARED, A/C DIVERTED TO STL LANDED SAFELY. FOUND HYD LINE FROM TOP OF CASE DRAIN MANIFOLD TO SERVICE PORT CHAFED THROUGH. REMOVED AND REPLACED LINE. NO FURTHER DEFECTS NOTED.