From the NannyMUD documentation

LAST CHANGE

2000-12-19

COMMAND

NAME
        shutdown - kill the game immediatly


AVAILABILITY
	This command is available to the current and former admin only.

SYNTAX
	shutdown 

DESCRIPTION
	Shutdown the game immediately. Don't do this if you don't have a very
	good reason for it. If possible, give players time to sell their
	things and save. If possible you should use armageddon (/obj/shut.c)
	for this purpose instead.