Based on years of watching TV news reports, I can imagine the day in Universal School of Journalism when they dealt with "How to End Your TV Report."
The cardinal rule, never to be violated, is: Do not end on a positive note, never. Several options are available:
1. Suggest that something awful could still go wrong.
2. Suggest a countervailing trend.
3. Raise a question that qualifies any optimistic developments in your piece.
4. Use your imagination to suggest that somehow the future is still in doubt, so viewers should tune in next time.
5. Say anything just as long as it is negative in some way.
That appears to be the one thing that all the students learned well.