NoMethodError in Events#show

Showing app/views/events/show.html.erb where line #30 raised:

undefined method `name' for nil:NilClass

Extracted source (around line #30):

27: 
28: 	<span class="list_date">
29: 
30: 		[<%= @event.department.name %>] </span> 
31: 
32: 
33: <% if admin? %>

RAILS_ROOT: /usr/local/apache2/htdocs/cityofmarshall

Application Trace | Framework Trace | Full Trace
/usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.18/lib/active_support/whiny_nil.rb:52:in `method_missing'
/usr/local/apache2/htdocs/cityofmarshall/app/views/events/show.html.erb:30:in `_run_erb_app47views47events47show46html46erb'
/usr/local/apache2/htdocs/cityofmarshall/app/controllers/events_controller.rb:52:in `show'

Request

Parameters:

{"id"=>"579"}

Show session dump

Response

Headers:

{"Content-Type"=>"text/html",
 "Cache-Control"=>"no-cache"}