Root can't remove file

[Dave Feustel <dfeustel_(_at_)_mindspring_(_dot_)_com>]

I attempted to remove a directory tree
using rm -rf but got a bunch of error
messages that I had a non-empty directory.
Drilling down I found a file named README
of length 0, owned by root/wheel with permissions
rw-rw----.
All attempts as root to delete, move or chown this file fail,
although I can write to it.

How can I get rid of it?

Thanks,
Dave Feustel
1-260-422-5330