I have a LG phone, android version 10. How do I remove a "Florida Blue Alert" from almost 2 weeks ago? I can't even see the actual message any more, just a web link, which doesn't work. As I recall, it showed a couple of views of some man, a fugitive, I think. Typing the link into my laptop browser gets me a screen saying the alert has been cancelled and the situation resolved. Swiping left and/or right gets me nothing.
Go to Messages > click the three dotted menu in the top tight corner > Settings > Advanced > Wireless emergency alerts.
You should now see a list of alerts you have received and you should be able to remove them either individually or all at once via the three dotted menu in the top right corner.