Reports showed that at least four Klingon ships had entered the Firaz system at one time or another; however, none were ever seen to leave. Orbital surveys made of Rex Dacut after the war found what might be two crash sites from the Klingon ships or, at least, their command pods, but there was no sign of any survivors. At least three landing parties, some Starfleet, attempted to survey and explore the planet's surface, but each disappeared without a trace.
Starfleet placed a beacon marking the whole system as prohibited, forbidding approach for any reason, including emergency landings. Nevertheless, a ship was lost in the area at least once a year, likely containing prospectors seeking the resources of Rex Dacut described by old Orion records, and not checking the modern Starfleet ones (FASA RPG module: The Orions: Book of Common Knowledge).