Deep Space 6

Deep Space 6 was a Federation Starbase designed in the early 2360s as a replacement for Deep Space 1 along the Romulan Neutral Zone. In 2363, during construction of the station, a freak explosion killed the team and destroyed most of the partially completed station. Tal Shiar involvement was suspected by Starfleet Intelligence, but has not been proven. The salvageable remains were later used to build Deep Space 7

(RPG Game Book: Star Trek Deep Space Nine: Core Game Book (LUG RPG))