"CBS Detroit," is part of the CBS Television Stations Group (as is sister station WKBD), one of the largest broadcast groups in the country. Locally, WWJ-TV and WKBD-TV operate as one of a number of "duopoly" markets in the United States. In 2001, WWJ-TV moved their offices and production facilities into WKBD-TV's facilities in Southfield.  The Emergency solution provided by VES protects the infrastructure and one of the largest broadcasting towers in the state.