As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ROC-DCA FLIGHT#3950. CREW REPORTED THAT THEY HAD INDICATION THAT #2 HYDRAULIC SYSTEM HAD LOST ALL FLUID. EMERGENCY DECLARED, AIRCRAFT LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE FOUND HYDRAULIC LINE BY FLAP MOTOR LEAKING. LINE REPLACED WITH AN INTERIM FLEX LINE. #2 ENGINE DRIVEN HYDRAULIC PUMP REPLACED. GROUND RUN OF ENGINE REVEALED NO LEAKS, OPERATIONAL CHECK GOOD. AIRCRAFT RETURNED TO SERVECE.