diff --git a/outage_detector/main.py b/outage_detector/main.py
index 571cc23..a6bfd44 100644
--- a/outage_detector/main.py
+++ b/outage_detector/main.py
@@ -18,12 +18,30 @@ class LogEntry:
 
 
 class Outage:
-    '''Class describing an outage.'''
+    '''
+        Class describing an outage.
 
-    def __init__(self, start: LogEntry, end: LogEntry):
+        `self.start` The start of the outage represented by a LogEntry object.
+
+        `self.end` The end of an outage represented by a LogEntry object.
+        Could be None to represent that the outage is still ongoing.
+    '''
+
+    def __init__(self, start: LogEntry, end: None | LogEntry = None):
         self.start = start
         self.end = end
 
+    def duration(self) -> datetime:
+        '''
+            Return the duration of the outage as datetime object.
+            If the outage does not have an end, the time from the start to now will be returned.
+        '''
+
+        if self.end is None:
+            return self.end.date - datetime.now()
+        else:
+            return self.end.date - self.start.date
+
 
 def printOutages(filepath: str, time: int) -> None:
     '''
@@ -54,27 +72,26 @@ def printOutages(filepath: str, time: int) -> None:
     # We consider the time of subsequent failed connection attempts to the same host an outage.
     outages: list = []
     last_failed = False
-    outage_start = None
-    for entries in log_by_host.values():
+
+    for _, entries in sorted(log_by_host.items()):  # sort by hostname
+
         for entry in entries:
 
             # Start a new outage.
             if entry.failed and not last_failed:
-                outage_start = entry
+                outages.append(Outage(entry))
                 last_failed = True
 
             # End an outage.
             elif not entry.failed and last_failed:
-                outages.append(Outage(outage_start, entry))
+                outages[-1].end = entry
                 last_failed = False
 
     # Print the outages.
     for outage in outages:
 
         # Get duration of outage in hours and minutes.
-        outage_duration = round(
-            (outage.end.date - outage.start.date).seconds / 60
-        )
+        outage_duration = round(outage.duration().seconds / 60)
 
         # Skip printing if outage is shorter than the minimum duration.
         if outage_duration < time: