A Twin Cities man found himself among stunned onlookers Monday as the famed spire that has long pierced the Parisian sky from atop the Notre Dame Cathedral collapsed in an orange crackle.

Tom Northenscold of Plymouth was out for a walk along the Seine River during a dream trip to Paris when he noticed the plume of smoke above the blaze that engulfed the upper section of the beloved 12th-century cathedral as it was undergoing renovations.

Northenscold, 61, said he first saw the smoke from across the Seine and "had to check Apple Maps to make sure that it was in fact Notre Dame burning."

Before too long, he saw the flames climb "up the spire and then spread over the entire roof line to the front of the church," a disaster coming less than a week before Easter and amid Holy Week commemorations.

Hundreds of people lined up on bridges around the island on which the cathedral is built, watching in shock as acrid smoke rose in plumes from Notre Dame, the most famous of the Gothic cathedrals of the Middle Ages and one of the world's most beloved structures.

As the wooden spire collapsed, "you could hear the gasps from the onlookers," Northenscold said, adding that he felt himself overcome with disbelief and shock.

Northenscold said he retired in 2013 as the chief information officer at St. Jude Medical, and he and his wife, Priscilla, were on an extended visit to Paris, now that they are empty nesters.

Since leaving the corporate world, he has made photography his creative outlet.

"Little did I know it would be put to such an important use," he said. "Eventually, what hit me was that I was witnessing history in the making, and it was horrific to see."

The Associated Press contributed to this report. Paul Walsh • 612-673-4482