On 7 Oct 2006 20:00:44 -0700, wrote:

"Glue it back on".

The bottom-most hardiplank board hangs low. Behind the piece that broke
off, there is nothing to "glue" it to.

That's why you keep a bucket of scrap wood in your garage.
You will make a backing out of a scrap piece of 1x4 and a couple of
door shims and contact cement.

Every home should have a package of door shims for just such
occasions.