<!DOCTYPE html>
<html>
    <head>
        <title>auto-height multicol with break</title>
        <style>
            .mc { float:left; width:9em; padding:0 0.5em; }
            .gap { float:left; width:1em; }
        </style>
    </head>
    <body style="min-width:40em;">
        <div style="float:left; background:olive;">
            <div class="mc">
                first column<br>
            </div>
            <div class="gap">&nbsp;</div>
            <div class="mc">
                second column<br>
                second column<br>
                second column<br>
                second column<br>
                second column<br>
                second column<br>
            </div>
            <div class="gap">&nbsp;</div>
            <div class="mc">
                third column<br>
                third column<br>
                third column<br>
                third column<br>
            </div>
        </div>
    </body>
</html>