How Do I Close/De-activate/Delete my HN Account?

Hi, My account has been deaded. I haven't received any explanation as to why this occurred, and in fact I wasn't aware of it until someone managed to get a message to me that it was.

I don't care really, if HN wants to dead my account, fine, but I should at least be able to close, delete or remove it.

Or, can someone tell me if dead accounts are automatically removed after a period of time?

Thanks,

o2sd