Is it Winston Churchill's funeral?
Olof Palme?
Is this when you crazy Swedes changed overnight from driving on the left to driving on the right?
Is it the night ABBA won the Eurovision Song Contest?What else ever happened in Sweden?
No it isn't. I don't think there was a need for any dogs that night.Hint: the event that caused this crowd has generated a diagnosis.
Acute herring intoxication? That would be sill-y.
You of all people should be able to guess from that hint.