there are many theories, but many historians believe they were destroyed by a tidal wave that was triggered by a volcanic eruption, or the mycenaeans destroyed them
There are various theories, including a huge earthquake, economic failure and also the unknown 'dark age'. also the Minoan/mycenean cultural clash/absorption
When you ask about disappearing, are you talking about just disappear so no one will know where you are? If it is all you can do is move to another state without no one knowing you are moving. Maybe...