If you try with tr or td tag to give word-wrap: break-word style css then it will not affect. When i was try to give word wrap css on my td tag it was not working same as for i did try with span tag but same result. But when i take div tag it was working so if you are give directly on td or span then take div tag inside td tag and give css this way:
<pre class="prettyprint lang-html">
<td><div style="word-wrap: break-word;width:20px">My Level</div></td>
Maybe this post can help you.......