diff --git a/src/micropolisj/engine/MapScanner.java b/src/micropolisj/engine/MapScanner.java
index 9e1272c..b126795 100644
--- a/src/micropolisj/engine/MapScanner.java
+++ b/src/micropolisj/engine/MapScanner.java
@@ -746,13 +746,10 @@ class MapScanner
 					if (isAnimated(thCh))
 						continue;
 
-					thCh &= LOMASK;
-					if (thCh < RUBBLE || thCh >= ROADBASE)
+					if (!isIndestructible(thCh))
 					{  //not rubble, radiactive, on fire or flooded
 
-						city.setTile(xx,yy,(char)
-						(zoneBase)
-						);
+						city.setTile(xx,yy,(char) zoneBase);
 					}
 				}
 			}
diff --git a/src/micropolisj/engine/TileConstants.java b/src/micropolisj/engine/TileConstants.java
index 2bb596e..25ce7f2 100644
--- a/src/micropolisj/engine/TileConstants.java
+++ b/src/micropolisj/engine/TileConstants.java
@@ -336,6 +336,12 @@ public class TileConstants
 		return (tmp >= FIREBASE && tmp < ROADBASE);
 	}
 
+	public static boolean isIndestructible(int tile)
+	{
+		int tmp = tile & LOMASK;
+		return tmp >= RUBBLE && tmp < ROADBASE;
+	}
+
 	public static boolean isRadioactive(int tile)
 	{
 		int tmp = tile & LOMASK;