diff --git a/game/src/ltn/connectivity.rs b/game/src/ltn/connectivity.rs
index 4fcda2821f..43bc80cade 100644
--- a/game/src/ltn/connectivity.rs
+++ b/game/src/ltn/connectivity.rs
@@ -77,7 +77,6 @@ impl Viewer {
             .iter()
             .filter(|c| c.is_disconnected())
             .count();
-        // TODO Also add a red outline to them or something
         let warning = if disconnected_cells == 0 {
             String::new()
         } else {
diff --git a/game/src/ltn/draw_cells.rs b/game/src/ltn/draw_cells.rs
index f5958d12b8..04ba60b353 100644
--- a/game/src/ltn/draw_cells.rs
+++ b/game/src/ltn/draw_cells.rs
@@ -18,6 +18,7 @@ lazy_static::lazy_static! {
     ];
 }
 const CAR_FREE_COLOR: Color = Color::GREEN;
+const DISCONNECTED_COLOR: Color = Color::RED;
 
 /// Partition a neighborhood's boundary polygon based on the cells. Currently this discretizes
 /// space into a grid, so the results don't look perfect, but it's fast. Also returns the color for
@@ -83,6 +84,8 @@ pub fn draw_cells(map: &Map, neighborhood: &Neighborhood) -> (GeomBatch, Vec<Col
     for (idx, cell) in neighborhood.cells.iter().enumerate() {
         if cell.car_free {
             cell_colors[idx] = CAR_FREE_COLOR;
+        } else if cell.is_disconnected() {
+            cell_colors[idx] = DISCONNECTED_COLOR;
         }
     }