diff --git a/OpenRA.Game/Actor.cs b/OpenRA.Game/Actor.cs
index 215b435f51..9028824c85 100755
--- a/OpenRA.Game/Actor.cs
+++ b/OpenRA.Game/Actor.cs
@@ -18,10 +18,10 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using System.Drawing;
 using System.Linq;
-using System;
 using OpenRA.FileFormats;
 using OpenRA.GameRules;
 using OpenRA.Traits;
diff --git a/OpenRA.Game/Traits/LineBuild.cs b/OpenRA.Game/Traits/LineBuild.cs
index c7c1d7fb5b..bb08f67873 100644
--- a/OpenRA.Game/Traits/LineBuild.cs
+++ b/OpenRA.Game/Traits/LineBuild.cs
@@ -18,18 +18,12 @@
  */
 #endregion
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using OpenRA.Effects;
-using OpenRA.GameRules;
-using OpenRA.Traits.Activities;
-
 namespace OpenRA.Traits
 {
 	public class LineBuildInfo : TraitInfo<LineBuild>
 	{
 		public readonly int Range = 5;
 	}
+
 	public class LineBuild {}
 }
diff --git a/OpenRA.Game/Traits/TraitsInterfaces.cs b/OpenRA.Game/Traits/TraitsInterfaces.cs
index b92307ef18..b3fb2c8de1 100644
--- a/OpenRA.Game/Traits/TraitsInterfaces.cs
+++ b/OpenRA.Game/Traits/TraitsInterfaces.cs
@@ -20,7 +20,6 @@
 
 using System.Collections.Generic;
 using System.Drawing;
-using OpenRA.FileFormats;
 using OpenRA.GameRules;
 using OpenRA.Graphics;
 
diff --git a/OpenRA.Game/Traits/Wall.cs b/OpenRA.Game/Traits/Wall.cs
index 835869a80c..284de0f469 100644
--- a/OpenRA.Game/Traits/Wall.cs
+++ b/OpenRA.Game/Traits/Wall.cs
@@ -18,8 +18,39 @@
  */
 #endregion
 
+using System.Collections.Generic;
+using System.Linq;
+using OpenRA.GameRules;
+
 namespace OpenRA.Traits
 {
-	public class WallInfo : TraitInfo<Wall> {}
-	public class Wall {}
+	public class WallInfo : ITraitInfo
+	{
+		public readonly UnitMovementType[] CrushableBy = { };
+
+		public object Create(Actor self) { return new Wall(self); }
+	}
+
+	public class Wall : ICrushable, IOccupySpace
+	{
+		readonly Actor self;
+		public Wall(Actor self)
+		{
+			this.self = self;
+			self.World.WorldActor.traits.Get<UnitInfluence>().Add(self, this);
+		}
+
+		public IEnumerable<int2> OccupiedCells() { yield return self.Location; }
+
+		public void OnCrush(Actor crusher) { self.InflictDamage(crusher, self.Health, null); }
+		public bool IsCrushableBy(UnitMovementType umt, Player player)
+		{
+			return self.Info.Traits.Get<WallInfo>().CrushableBy.Contains(umt);
+		}
+
+		public bool IsPathableCrush(UnitMovementType umt, Player player)
+		{
+			return IsCrushableBy(umt, player);
+		}
+	}
 }
diff --git a/OpenRA.Game/Widgets/PostGameWidget.cs b/OpenRA.Game/Widgets/PostGameWidget.cs
index 2927f223a1..c5d27385cf 100644
--- a/OpenRA.Game/Widgets/PostGameWidget.cs
+++ b/OpenRA.Game/Widgets/PostGameWidget.cs
@@ -1,3 +1,23 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007,2009,2010 Chris Forbes, Robert Pepperell, Matthew Bowra-Dean, Paul Chote, Alli Witheford.
+ * This file is part of OpenRA.
+ * 
+ *  OpenRA is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ * 
+ *  OpenRA is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ * 
+ *  You should have received a copy of the GNU General Public License
+ *  along with OpenRA.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#endregion
+
 using System.Drawing;
 using System.Linq;
 using OpenRA.Traits;
diff --git a/OpenRA.Game/WorldUtils.cs b/OpenRA.Game/WorldUtils.cs
index cd81f2007b..75c7c465ff 100755
--- a/OpenRA.Game/WorldUtils.cs
+++ b/OpenRA.Game/WorldUtils.cs
@@ -139,9 +139,9 @@ namespace OpenRA
 		public static bool CanPlaceBuilding(this World world, string name, BuildingInfo building, int2 topLeft, Actor toIgnore)
 		{
 			var res = world.WorldActor.traits.Get<ResourceLayer>();
-			return !Footprint.Tiles(name, building, topLeft).Any(
-				t => !world.Map.IsInMap(t.X, t.Y) || res.GetResource(t) != null || !world.IsCellBuildable(t,
-					building.WaterBound, toIgnore));
+			return Footprint.Tiles(name, building, topLeft).All(
+				t => world.Map.IsInMap(t.X, t.Y) && res.GetResource(t) == null &&
+					world.IsCellBuildable(t, building.WaterBound, toIgnore));
 		}
 
 		public static bool IsVisible(this Actor a)
diff --git a/mods/ra/defaults.yaml b/mods/ra/defaults.yaml
index 4d5ee2c65d..ffdd08575d 100644
--- a/mods/ra/defaults.yaml
+++ b/mods/ra/defaults.yaml
@@ -61,12 +61,12 @@
 	Category: Building
 	Building:
 		Dimensions: 1,1
-		Footprint: x
+		Footprint: y
 		BuildSounds: placbldg.aud
 		Capturable: false
 		BaseNormal: no
 		Crewed: no
-		Sight: 0
+		Sight: 0	
 	Wall:
 	LineBuild:
 	Selectable:
diff --git a/mods/ra/structures.yaml b/mods/ra/structures.yaml
index 7a372e7afc..08516078f9 100644
--- a/mods/ra/structures.yaml
+++ b/mods/ra/structures.yaml
@@ -818,6 +818,8 @@ SBAG:
 	Building:
 		HP: 100
 		Armor: none
+	Wall:
+		CrushableBy: Wheel, Track
 
 FENC:
 	Category: Defense
@@ -833,6 +835,8 @@ FENC:
 	Building:
 		HP: 100
 		Armor: none
+	Wall:
+		CrushableBy: Track
 
 BRIK:
 	Category: Defense
@@ -858,14 +862,21 @@ CYCL:
 		Armor: none
 	RenderBuildingWall:
 		DamageStates: 3
+	Wall:
+		CrushableBy: Track
+		
 BARB:
 	Inherits: ^Wall
 	Building:
 		HP: 100
 		Armor: none
+	Wall:
+		CrushableBy: Track
 
 WOOD:
 	Inherits: ^Wall
 	Building:
 		HP: 100
-		Armor: none
\ No newline at end of file
+		Armor: none
+	Wall:
+		CrushableBy: Track