The Daily News is reporting that the tunnels that carry the 4/5 and F trains from Brooklyn to Manhattan have been drained, inspected, and found free of major damage. As soon as power is restored to the areas downtown, and trains can be powered, they’re ready to run test trains through the tunnels. 

Running the Test Trains is the last step before the tunnels can be reopened fully, and brooklyn commuters can kiss the bus bridge a final farewell. 

If all goes well this means subway service between brooklyn and manhattan could be back on-line the day after power is restored to downtown. 

Source ex-genius