American Eagle flight AA4194, an Embraer ERJ-145LR, suffered a runway excursion after landing on runway 06 at Freeport-Grand Bahama International Airport, Bahamas. After touchdown, both pilots described experiencing uncommanded braking of the aircraft. Attempts to control the aircraft on the runway were unsuccessful as it veered to the right of runway centerline, eventually exiting the runway at a distance of approximately 3715 ft from the runway threshold. The left main gear collapsed during the event and the aircraft eventually came to rest approximately 15 ft from the right of the runway’s edge. PROBABLE CAUSE: Based on evidence gathered, CVR and FDR data analysis and analysis conducted of suspected components, the probable cause of the heavy braking action that resulted in the runway excursion could not be replicated or determined. Results of functional tests of components suspected of contributing to the heavy braking action that occurred are as follows: – Brake control unit (BCU), PASS – Emergency parking brake pressure switch PASS – Emergency parking brake handle and cable PASS – Parking brake valve – all tests passed except for internal leakage in the “Off” position – 4 drops in 5 min (requirement: not to exceed 1 drop in 5 min). The component manufacturer and Embraer stated that this issue would have no effect on braking performance but could result in excessive hydraulic pump operations in order to maintain system pressure. Additionally, slight deviations were noted on operational test but this was determined to have minimal effect on brake pressure application.