Force kill a process?

[Hans du Plooy <koffiejunkielistlurker@koffiejunkie.za.net>]

mercury:/home/www/web8/web# ps ax | grep ftp
 3123 ?        Ds     0:00 proftpd: (accepting connections)
18183 ?        D      0:00 /usr/sbin/proftpd
19079 pts/0    D      0:00 /usr/sbin/proftpd

How do I kill this?  I'm not exactly in a position to restart the
server.

Thanks
Hans