diff --git a/universe/engine.py b/universe/engine.py
index 08765e2..73fc86d 100644
--- a/universe/engine.py
+++ b/universe/engine.py
@@ -24,12 +24,14 @@ class Entity:
         for component in self.__dict__.get('_components', {}).values():
             if name in component._fields:
                 self.__dict__['_data'][name] = value
+                return
         self.__dict__[name] = value
 
     def __delattr__(self, name):
         for component in self.__dict__.get('_components', {}).values():
             if name in component._fields:
                 del self.__dict__['_data'][name]
+                return
         del self.__dict__[name]
 
     def __contains__(self, key):
diff --git a/universe/systems.py b/universe/systems.py
index 7a7043b..f06579c 100644
--- a/universe/systems.py
+++ b/universe/systems.py
@@ -119,3 +119,6 @@ class PopulationGrowthSystem:
             growth_rate = 1 + Decimal(species.growth_rate) / 100
             population *= growth_rate
             entity.population = int(population.to_integral_value())
+            if entity.population <= 0:
+                del entity.population
+                del entity.owner_id

Owned planets that have no population should lose ownership
Also, an explicit 0 population should be removed.
diff --git a/tests/test_systems.py b/tests/test_systems.py
index 96ef1ce..4d07dc0 100644
--- a/tests/test_systems.py
+++ b/tests/test_systems.py
@@ -67,3 +67,38 @@ class PopulationTestCase(unittest.TestCase):
                 }
             }
         )
+
+    def test_lose_ownership(self):
+        state = {
+            'turn': 2500,
+            'width': 1000,
+            'entities': {
+                0: {
+                    'type': 'species',
+                    'name': 'Human',
+                    'plural_name': 'Humans',
+                    'growth_rate': 15,
+                },
+                1: {
+                    'type': 'planet',
+                    'population': 0,
+                    'x': 480,
+                    'y': 235,
+                    'gravity': 50,
+                    'temperature': 50,
+                    'radiation': 50,
+                    'ironium_conc': 50,
+                    'boranium_conc': 50,
+                    'germanium_conc': 50,
+                    'owner_id': 0,
+                    'queue': [],
+                },
+            }
+        }
+
+        S = engine.GameState(state, {})
+        results = S.generate()
+
+        self.assertEqual(len(results['entities']), 2)
+        self.assertNotIn('population', results['entities'][1])
+        self.assertNotIn('owner_id', results['entities'][1])

pip install -e .
parse_log_pytest
pytest
pytest
pip install tox tox-travis
3.7
pytest --no-header -rA --tb=line --color=no -p no:cacheprovider -W ignore::DeprecationWarning
attrs @ file:///croot/attrs_1668696182826/work
certifi @ file:///croot/certifi_1671487769961/work/certifi
distlib==0.3.9
filelock==3.12.2
flit_core @ file:///opt/conda/conda-bld/flit-core_1644941570762/work/source/flit_core
importlib-metadata==6.7.0
iniconfig @ file:///home/linux1/recipes/ci/iniconfig_1610983019677/work
packaging==24.0
platformdirs==4.0.0
pluggy==1.2.0
py @ file:///opt/conda/conda-bld/py_1644396412707/work
pytest==7.1.2
six==1.17.0
tomli @ file:///opt/conda/conda-bld/tomli_1657175507142/work
tox==3.28.0
tox-travis==0.13
typing_extensions==4.7.1
-e git+https://github.com/jbradberry/universe.git@7caaa4890d34219fd03b24d85b82a1241e06af07#egg=universe
virtualenv==20.26.6
zipp @ file:///croot/zipp_1672387121353/work

name: universe
channels:
  - defaults
  - https://repo.anaconda.com/pkgs/main
  - https://repo.anaconda.com/pkgs/r
  - conda-forge
dependencies:
  - _libgcc_mutex=0.1=main
  - _openmp_mutex=5.1=1_gnu
  - attrs=22.1.0=py37h06a4308_0
  - ca-certificates=2025.2.25=h06a4308_0
  - certifi=2022.12.7=py37h06a4308_0
  - flit-core=3.6.0=pyhd3eb1b0_0
  - importlib_metadata=4.11.3=hd3eb1b0_0
  - iniconfig=1.1.1=pyhd3eb1b0_0
  - ld_impl_linux-64=2.40=h12ee557_0
  - libffi=3.4.4=h6a678d5_1
  - libgcc-ng=11.2.0=h1234567_1
  - libgomp=11.2.0=h1234567_1
  - libstdcxx-ng=11.2.0=h1234567_1
  - ncurses=6.4=h6a678d5_0
  - openssl=1.1.1w=h7f8727e_0
  - pip=22.3.1=py37h06a4308_0
  - py=1.11.0=pyhd3eb1b0_0
  - pytest=7.1.2=py37h06a4308_0
  - python=3.7.16=h7a1cb2a_0
  - readline=8.2=h5eee18b_0
  - setuptools=65.6.3=py37h06a4308_0
  - sqlite=3.45.3=h5eee18b_0
  - tk=8.6.14=h39e8969_0
  - tomli=2.0.1=py37h06a4308_0
  - wheel=0.38.4=py37h06a4308_0
  - xz=5.6.4=h5eee18b_1
  - zipp=3.11.0=py37h06a4308_0
  - zlib=1.2.13=h5eee18b_1
  - pip:
      - distlib==0.3.9
      - filelock==3.12.2
      - importlib-metadata==6.7.0
      - packaging==24.0
      - platformdirs==4.0.0
      - pluggy==1.2.0
      - six==1.17.0
      - tox==3.28.0
      - tox-travis==0.13
      - typing-extensions==4.7.1
      - virtualenv==20.26.6
prefix: /opt/conda/envs/universe

tests/test_systems.py::PopulationTestCase::test_lose_ownership
tests/test_systems.py::PopulationTestCase::test_population_growth
universe/systems.py universe/engine.py
universe/systems.py universe/engine.py