The US has no national siren system; there are just state and local ones. I've heard siren tests every once in a while living in San Francisco, but there's zero

The US has no national siren system; there are just state and local ones. I've heard siren tests every once in a while living in San Francisco, but there's zero public education about their meaning or appropriate responses. (This false alarm was a push alert sent to cell phones. What about people who don't have a cell phone on them when the alert comes? ... good luck)