diff --git a/src/aligned_textgrid/aligned_textgrid.py b/src/aligned_textgrid/aligned_textgrid.py
index ea8ad1a..8b2c7c4 100644
--- a/src/aligned_textgrid/aligned_textgrid.py
+++ b/src/aligned_textgrid/aligned_textgrid.py
@@ -41,6 +41,8 @@ class for each tier within each tier group. Say, if only the first speaker
             The entry classes for each tier within a tier group.
         tier_groups (list[TierGroup] | list[]):
             A list of `TierGroup` or an empty list.
+        tier_names (list[str]):
+            A list of names for tiers in tier_groups.
         xmax (float):
             Maximum time
         xmin (float):
@@ -178,8 +180,6 @@ def _init_empty(self):
         self.contains = self.tier_groups
         self.entry_classes = []
         self.tg_tiers = None
-        self.xmax = 0.0
-        self.xmin = 0.0
     
     def _nestify_tiers(
         self,
@@ -276,14 +276,20 @@ def _relate_tiers(self):
     
     @property
     def tier_names(self):
+        if len(self) == 0:
+            raise ValueError('No tier names in an empty TextGrid.')
         return [x.tier_names for x in self.tier_groups]
 
     @property
     def xmin(self):
+        if len(self) == 0:
+            raise ValueError('No minimum time for empty TextGrid.')
         return np.array([tgroup.xmin for tgroup in self.tier_groups]).min()
 
     @property
     def xmax(self):
+        if len(self) == 0:
+            raise ValueError('No maximum time for empty TextGrid.')
         return np.array([tgroup.xmax for tgroup in self.tier_groups]).max()
     
     def interleave_class(
diff --git a/tests/test_aligned_textgrid.py b/tests/test_aligned_textgrid.py
index 14c19fd..fc4d3f7 100644
--- a/tests/test_aligned_textgrid.py
+++ b/tests/test_aligned_textgrid.py
@@ -138,8 +138,10 @@ def test_get_class_by_name(self):
 
         missing_class1 = self.atg1.get_class_by_name("Foo")
         missing_class2 = self.atg2.get_class_by_name("Foo")
+        missing_class4 = self.atg4.get_class_by_name("Foo")
         assert missing_class1 is None
         assert missing_class2 is None
+        assert missing_class4 is None
 
         target_classes = self.atg3.get_class_by_name("MyWord")
         assert len(target_classes) > 1
@@ -158,6 +160,15 @@ def test_empty_class_indexing(self):
             empty_idx_list = []
             self.atg4[empty_idx_list]
 
+    def test_empty_class_attributes(self):
+        with pytest.raises(ValueError):
+            self.atg4.xmin
+
+        with pytest.raises(ValueError):
+            self.atg4.xmax
+
+        with pytest.raises(ValueError):
+            self.atg4.tier_names
     
 class TestInGetLen:
     atg = AlignedTextGrid(