Michelle Obama was living the good life -- sipping wine on a dinner cruise in Paris -- when the Notre Dame Cathedral fire totally changed the mood ... and the course of the cruise.
The former First Lady was smiling as she boarded the Ducasse sur Seine Monday night -- just across from the Eiffel Tower -- for a dinner cruise experience along the Seine River with famous chef Alain Ducasse and others.
Michelle looked fit for a fancy, fun night on the luxury ship ... but things took a turn for the worse when word got around Notre Dame was going up in flames. As you can see in the pics ... everybody's happy faces turn concerned for the famed cathedral and the people of Paris.
The majesty of Notre Dame—the history, artistry, and spirituality—took our breath away, lifting us to a higher understanding of who we are and who we can be. Being here in Paris tonight, my heart aches with the people of France. Yet I know that Notre Dame will soon awe us again. https://t.co/p1mIDMbwe1
We're told the boat's captain ultimately made the decision to take a different route than planned for the cruise to avoid the Notre Dame fire ... and dinner was still served.
As we reported ... the cathedral is still standing after the massive fire, but the restoration process will be long and difficult.
BTW -- Michelle was in Paris for a conference at the AccorHotels Arena ... as part of her book tour for her best-seller, "Becoming."