}What am I doing wrong with the following switch statement. For some reason, all of them run each time.

For some reason the following switch statement runs all of them, it always does an alert on "1", but then on 2 as well each time..  What am I doing wrong?
var User = '1'; switch (User) { case '1': { alert('case 1); } case '2': { alert('case 2''); }
}

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