One way to do that is to sound the tornado sirens. I know when one goes off here and there is no weather warning or scheduled test the people either get online and ask other people or they call the police and then report it online. The first time it happened I was trying to find out what was going on and my wife told me the neighborhood Fakebook group already confirmed with the Sheriff that it was being repaired and should stop soon. That took about 3 minutes.