You can report this to Facebook requesting that they remove the account or memorialize the account.
From Facebook FAQ:
How do I report a deceased user or an account that needs to be
memorialized and deactivated or
deleted?
Memorializing the account:
Please report this information here so
that we can memorialize this person’s
account. Memorializing the account
restricts profile access to confirmed
friends only. Please note that in
order to protect the privacy of the
deceased user, we cannot provide login
information for the account to anyone.
We do honor requests from close family
members to close the account
completely.
Removing the account:
Immediate family
members may request the removal of a
loved one’s account. This will
completely remove the account from
Facebook so that no one can view it.
We will not restore the account or
provide information on its content
unless required by law. If you are
requesting a removal and are not an
immediate family member of the
deceased, your request will not be
processed, but the account will be
memorialized.
To make a request to memorialize or
remove a profile, please do so here.
If you have a special request
regarding a deceased user's account,
please use this form. Please note that
this form is only to be used for
accounts that have already been
memorialized.
The Facebook FAQ page can be found here