After ownership of Carter Publications transferred to his familial heirs after Carter suffered a fatal heart attack two years before, in early 1957, NBC threatened to strip WBAP-TV of its affiliation if it did not agree to move its transmitter eastward to reach the entire Dallas area. Belo had attempted to get an exclusive NBC affiliation first, and approached the network with an offer to make WFAA its exclusive affiliate for the entire market. The network also approached the Roosevelt family-owned Texas State Network about affiliating with independent station KFJZ-TV (channel 11, now CBS owned-and-operated station KTVT), which had earlier moved its transmitter to the antenna farm in Cedar Hill. Carter's heirs—who initially did not want to move the transmitter closer to Dallas, in their aim to continue Carter's legacy of civic boosterism for Fort Worth—eventually agreed to NBC's demands that it move WBAP-TV's transmitter facilities to Cedar Hill, installing a transmitter antenna on a candelabra tower that was already shared by WFAA and KRLD-TV, and operate it at a higher effective radiated power strong enough to adequately cover Dallas. WFAA lost its NBC affiliation on September 1, 1957, as the network had awarded WBAP-TV the exclusive affiliation for the Dallas–Fort Worth market as a byproduct of the transmitter relocation and signal boost; this left Channel 8 as an exclusive affiliate of the then-low-rated ABC.