When Tom was in Cuba when the Pope visited, he was obviously having some trouble hearing the director in his earpiece. One time they came back from commercial and her was looking at his papers...you could her someone say "Tom!" and he looked up.

Another time he was standing in front of that big screen they use and you could hear a snapping noise and the whole screen shut off.

Another time, after the Alaska Air crash, Robert Hager was in front of NTSB headquarters for the Today Show and they came back to him live from a report. He was yelling "I lost my audio I lost my audio"

Finally, a report on a gunshow once aired about halfway on Nightly News with no narration!