diff --git a/core/src/com/unciv/logic/city/CityInfo.kt b/core/src/com/unciv/logic/city/CityInfo.kt
index 20814c0d21..26e18224f7 100644
--- a/core/src/com/unciv/logic/city/CityInfo.kt
+++ b/core/src/com/unciv/logic/city/CityInfo.kt
@@ -161,7 +161,7 @@ class CityInfo {
         expansion.nextTurn(stats.culture)
         if(isBeingRazed){
             population.population--
-            if(population.population==0){
+            if(population.population<=0){ // there are strange cases where we geet to -1
                 civInfo.addNotification("$name {has been razed to the ground}!",location, Color.RED)
                 destroyCity()
                 if(isCapital() && civInfo.cities.isNotEmpty()) // Yes, we actually razed the capital. Some people do this.
@@ -170,8 +170,10 @@ class CityInfo {
         }
         else population.nextTurn(stats.food)
 
-        health = min(health+20, getMaxHealth())
-        population.unassignExtraPopulation()
+        if(this in civInfo.cities) { // city was not destroyed
+            health = min(health + 20, getMaxHealth())
+            population.unassignExtraPopulation()
+        }
     }
 
     fun destroyCity() {
diff --git a/core/src/com/unciv/logic/city/CityStats.kt b/core/src/com/unciv/logic/city/CityStats.kt
index 9fef02290e..f1a7789ada 100644
--- a/core/src/com/unciv/logic/city/CityStats.kt
+++ b/core/src/com/unciv/logic/city/CityStats.kt
@@ -131,6 +131,8 @@ class CityStats {
         val happinessFromBuildings = cityInfo.cityConstructions.getStats().happiness.toInt().toFloat()
         newHappinessList ["Buildings"] = happinessFromBuildings
 
+        // we don't want to modify the existing happiness list because that leads
+        // to concurrency problems if we iterate on it while changing
         happinessList=newHappinessList
         return newHappinessList
     }