In non-IE browsers, changing the innerHTML of an element detaches its children, but leaves them intact. In IE, it also clears the innerhtml property of all children, detaching all descendants.

HowDoIInnterHtml.java

public class HowDoIInnerHtml implements EntryPoint {
  @Override
  public void onModuleLoad() {
    Element body = Document.get().getBody();

    DivElement newDiv = Document.get().createDivElement();
    newDiv.setClassName("foo");
    newDiv.setInnerText("Text in the div");

    SpanElement newSpan = Document.get().createSpanElement();
    newDiv.appendChild(newSpan);

    body.appendChild(newDiv);
    //page shows "Text in the div"

    Window.alert("newDiv.innerHTML? " + newDiv.getInnerHTML() +
        "\nspan is in div? " + (newSpan.getParentElement() == newDiv));
    //alert shows "Text in the div <span></span>", true

    body.setInnerHTML("");

    Window.alert("newDiv.innerHTML? " + newDiv.getInnerHTML() +
            "\nspan is in div? " + (newSpan.getParentElement() == newDiv));
    //alert shows "", false ???

    body.appendChild(newDiv);
    //page shows blank
  }
}