If I remember correctly, FNC was speculating it was terrorism before the second plane hit. I'll have to check my videotapes to confirm that, but I remember them even discussing the possibility it was Bin Laden. I also remember CNN still claimed it was an accident even after the second plane hit.
I caught it a little before the second plane hit and they were discussing the possiblity of it being an accident. They may have mentioned the terrorism aspect before I turned the TV on. We don't get cable so I don't think the reporting I heard was the same. We have to depend on ABC, CBS, NBC. I do remember clearly, though, that when the second plane it, it settled the issue, especially in my mind.