diff --git a/app/controllers/management/conferences_controller.rb b/app/controllers/management/conferences_controller.rb
index 262873a..c111310 100644
--- a/app/controllers/management/conferences_controller.rb
+++ b/app/controllers/management/conferences_controller.rb
@@ -1,11 +1,11 @@
 module Management
   class ConferencesController < ManagementController
-    before_action :assign_conference, only: [:edit, :update, :open_call_for_papers, :close_call_for_papers]
-    before_action :assign_conferences, only: [:index, :open_call_for_papers, :close_call_for_papers]
+    before_action :assign_conference, only: [:edit, :update, :show, :destroy, :open_call_for_papers, :close_call_for_papers]
+    before_action :assign_conferences, only: [:index, :destroy, :open_call_for_papers, :close_call_for_papers]
 
     def new
       @conference = Conference.new
-      3.times { @conference.tracks.build }
+      @conference.tracks.build(name: 'Track 1')
       @conference.halls.build(name: 'Hall 1')
     end
 
@@ -27,6 +27,15 @@ module Management
     def index
     end
 
+    def show
+    end
+
+    def destroy
+      @conference.destroy
+
+      render 'reload_table'
+    end
+
     def open_call_for_papers
       @conference.call_for_papers_open = true
       @conference.save
diff --git a/app/models/conference.rb b/app/models/conference.rb
index 72c8587..af02deb 100644
--- a/app/models/conference.rb
+++ b/app/models/conference.rb
@@ -8,12 +8,12 @@ class Conference < ActiveRecord::Base
 
   translates :title, :description
 
-  has_many :tracks, -> { order('id asc') }
+  has_many :tracks, -> { order('id asc') }, dependent: :destroy
   has_many :events, through: :tracks
   has_many :candidate_speakers, through: :events
-  has_many :halls
+  has_many :halls, dependent: :destroy
 
-  accepts_nested_attributes_for :tracks, :halls, allow_destroy: true
+  accepts_nested_attributes_for :tracks, :halls, reject_if: :all_blank, allow_destroy: true
 
   scope :future, -> { where('start_date >= ?', Date.today).order('start_date ASC') }
 
diff --git a/app/models/hall.rb b/app/models/hall.rb
index cb0c70e..1bf42eb 100644
--- a/app/models/hall.rb
+++ b/app/models/hall.rb
@@ -1,4 +1,6 @@
 class Hall < ActiveRecord::Base
   belongs_to :conference
   has_many :slots, dependent: :destroy
+
+  validates :name, presence: true
 end
diff --git a/app/models/track.rb b/app/models/track.rb
index f33bb85..3e9b598 100644
--- a/app/models/track.rb
+++ b/app/models/track.rb
@@ -1,6 +1,6 @@
 class Track < ActiveRecord::Base
   belongs_to :conference
-  has_many :events
+  has_many :events, dependent: :destroy
 
   validates :name, presence: true
   validates :color, presence: true, format: {with: /\A#?[a-f0-9]{6}\z/i}
diff --git a/app/views/management/conferences/_conference.html.slim b/app/views/management/conferences/_conference.html.slim
index b519ca1..91419d8 100644
--- a/app/views/management/conferences/_conference.html.slim
+++ b/app/views/management/conferences/_conference.html.slim
@@ -17,5 +17,5 @@ tr
         = fa_icon :eye
       = link_to edit_management_conference_path(conference), title: t('actions.edit.button', model: Conference.model_name.human), class: 'btn btn-primary'
         = fa_icon :edit
-      = link_to management_conference_path(conference), title: t('actions.destroy.button', model: Conference.model_name.human), class: 'btn btn-danger', method: :delete, data: {confirm: t('actions.are_you_sure')}
+      = link_to management_conference_path(conference), title: t('actions.destroy.button', model: Conference.model_name.human), class: ['btn', 'btn-danger', conference.events.any? ? 'disabled' : nil], remote: true, method: :delete, data: {confirm: t('actions.are_you_sure')}
         = fa_icon :trash
diff --git a/app/views/management/conferences/_form_halls.html.slim b/app/views/management/conferences/_form_halls.html.slim
index 76e9fd6..88ce9d8 100644
--- a/app/views/management/conferences/_form_halls.html.slim
+++ b/app/views/management/conferences/_form_halls.html.slim
@@ -1,6 +1,6 @@
 div#halls
   = form.simple_fields_for :halls do |ff|
-    .col-md-3
+    .col-md-4
       .panel.panel-default
         .panel-heading
           .panel-title
@@ -9,7 +9,7 @@ div#halls
           span.clearfix
         .panel-body
           = ff.input :name
-.col-md-3
+.col-md-4
   .panel.panel-default
     .panel-heading
       .panel-title