American describes ‘mass panic’ and ‘mayhem’ during attack on the Champs Elysees The man stopped to buy a rose for his wife, which may have saved their lives.

 -- An American who was near the Champs Elysees when a gunman opened fire on police in Paris described the scene as "mayhem" and "mass panic."

It was a beautiful night in Paris when Kentucky resident John Finney, his wife Angela and their three sons were walking on the Avenue des Champs Elysees after dinner and a day of sightseeing in one of the City of Light's most iconic destinations.

"This is the most expensive, most beautiful street in the world," Finney said he told his family. "We’ve got to see it at nighttime."

Then, Finney stopped to buy his wife a red rose from a street merchant near the Dior store -- a decision that could have saved the lives of him and his family.

"Thank goodness I did," Finney told ABC News. "Had I not stopped to get that rose for her, we would have been right on top of the shooter."

Finney then saw the gunman, dressed in all black, before he began to spray bullets at Parisian police.

"That's when panic set in," he said. "We were very terrified, obviously."

Angela Finney then yelled for everyone to run, Finney said. The couple's sons ran up the street, with their mother following behind them and Finney behind her, attempting to "block and shield them from any shots that were going."

Along with the Finney family, hundreds of other people were trying to escape the deadly scene.

"I mean, it was mass panic ... mayhem," Finney said. "People were falling down. People were stepping on people."

Finney said the family knew "right away" that they were in the middle of a "terrorist event" and described the shooter as having a "blank, dead look" on his face.

"He starts shooting. We're running. He continues to shoot, and we don't know where the bullets were at," Finney said, adding that the shots lasted for less than 40 seconds.

The father said the family was "absolutely" afraid for their lives.

"We were in the kill zone," he said. "We were definitely afraid."

As the family ran to safety, the manager of the watch store Swatch waved them into the building. After about 10 additional people ran in, the manger closed the metal gate. The group then waited in the basement of the store for two and a half hours.

The store employees "took care" of them, Finney said, providing them with food and coffee.

The family will not be shortening their trip, Finney said, adding that they will remain in Paris until Sunday, when they head for London.

Finney expressed a "love" for France and advised that other Americans not be deterred from coming there.

"To any other Americans who want to visit here, this is the country to come to," he said. "The French people are resilient. They're heroes. This is a beautiful country. They're beautiful people."

One policeman was killed and two others were injured in Thursday night's attack, which ISIS claimed responsibility for.

ABC News' Rym Momtaz contributed to this report.