This in from Notify NYC:
Notification issued 12/13/13 at 12:00 PM. Due to necessary roadway repairs, the Manhattan-bound Brooklyn Bridge will be closed to vehicular traffic overnight during the following dates/times: Saturday 12/14 from midnight to 7 AM, Sunday 12/15 from midnight to 9 AM, Monday 12/16 from midnight to 6 AM, and Monday thru Thursday nights, 12/16 to 12/19 from 11 PM to 6 AM (Friday morning, 12/20). Consider alternate routes during closures, including the Manhattan Bridge.
There’s more information at the DOT website.