If the pool hall's net access dies, the only alternative is a different internet line.
With a good cell phone, you can tether that phone's internet access (which comes from the cell tower) to the computers being used for streaming.
You could then use that net access as a backup to keep the stream going (if the connection is good enough) or possibly to broadcast voice only.
With a less advanced phone, you could still at least post on AZB forums that the stream is down, and those who think to check the forums will see the message and be reassured.