diff -r fef7f2d908bf -r 8842c71d16bf hedgewars/uLandGraphics.pas
--- a/hedgewars/uLandGraphics.pas	Mon Apr 21 16:51:14 2008 +0000
+++ b/hedgewars/uLandGraphics.pas	Mon Apr 21 18:43:07 2008 +0000
@@ -57,7 +57,7 @@
    begin
    if ((y + dy) and $FFFFFC00) = 0 then
       for i:= max(x - dx, 0) to min(x + dx, 2047) do
-          if (Land[y + dy, i] > 0) then dec(Land[y + dy, i]);
+          if (Land[y + dy, i] > 0) then dec(Land[y + dy, i]); // check > 0 because explosion can erase collision data
    if ((y - dy) and $FFFFFC00) = 0 then
       for i:= max(x - dx, 0) to min(x + dx, 2047) do
           if (Land[y - dy, i] > 0) then dec(Land[y - dy, i]);