diff --git a/src/micropolisj/engine/MapScanner.java b/src/micropolisj/engine/MapScanner.java
index b126795..5ff4da0 100644
--- a/src/micropolisj/engine/MapScanner.java
+++ b/src/micropolisj/engine/MapScanner.java
@@ -503,8 +503,7 @@ class MapScanner
 		{
 			for (int x = xpos-1; x <= xpos+1; x++)
 			{
-				char c = (char)(city.map[y][x] & LOMASK);
-				if (c >= FLOOD && c < ROADBASE) {
+				if (isIndestructible2(city.getTile(x,y))) {
 					// radioactive, on fire, or flooded
 					return false;
 				}
diff --git a/src/micropolisj/engine/TileConstants.java b/src/micropolisj/engine/TileConstants.java
index 25ce7f2..19d34c0 100644
--- a/src/micropolisj/engine/TileConstants.java
+++ b/src/micropolisj/engine/TileConstants.java
@@ -336,12 +336,20 @@ public class TileConstants
 		return (tmp >= FIREBASE && tmp < ROADBASE);
 	}
 
+	/** Used in repairZone(). */
 	public static boolean isIndestructible(int tile)
 	{
 		int tmp = tile & LOMASK;
 		return tmp >= RUBBLE && tmp < ROADBASE;
 	}
 
+	/** Used in zonePlop(). */
+	public static boolean isIndestructible2(int tile)
+	{
+		int tmp = tile & LOMASK;
+		return tmp >= FLOOD && tmp < ROADBASE;
+	}
+
 	public static boolean isRadioactive(int tile)
 	{
 		int tmp = tile & LOMASK;