Midnight Caller......

Yep. It was wake up get dressed and walk down eight floors to socialise with alll the other folk you will find down there with the false alarm fire call out. 
This is only the third time it has happened in many years and it often occurs because someone has burnt something and set off the smoke alarms in each apartment and does not know  about the override control in the apartment to stop things  becoming very public. 
Luckily we didn't have to walk back up.