As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PHL FLT 723 - EN ROUTE DUB TO PHL. DURING DESCENT INTO PHL, THE LT HYDRAULIC SYSTEM QUANTITY DECREASED TO ZERO AND THE SYSTEM PRESSURE LIGHT ILLUMINATED. ALSO, EICAS MESSAGE "G L HYD SYS PRESS" DISPLAYED. THE FLIGHT LANDED SAFELY AND WAS ABLE TO TAXI OFF THE RUNWAY, BUT WAS TOWED TO THE GATE. MAINTENANCE REPLACED A HYDRAULIC DRAIN TUBE. SYSTEM OPERATIONALLY AND LEAK CHECKS OK. (A)