The housekeepers in the corridor seemed confused but we went to the fire exit and walked down five flights of stairs to the lobby to mill with others.
Eventually we asked at the desk and an employee told us it was simply "training."
Apparently a letter was to have been delivered to our room yesterday but none had arrived - and we weren't the only guests surprised and a bit miffed.
Profuse apologies followed and the Guest Relations Manager, whom we had encountered by chance at the elevator, comped our parking and apologized again.
It was a great stay, despite the surprise ending.