Complex sentence: At some point in time, WECT added a third newscast to WSFX called "Fox Wilmington News at 6:30", which only aired on weeknights and attempted to compete against the national evening newscasts seen on the big three networks.
Split into simpler sentences: At some point in time, WECT added a third newscast to WSFX. This program, known as "Fox Wilmington News at 6:30", only aired on weeknights and attempted to compete against the national evening newscasts seen on the big three networks.