A spontaneous tribute to World War II veterans waiting for a flight out of the Detroit Metro Airport brought tears to the eyes onlookers.

As a group of 12 World War II veterans lined up to board Delta flight 98 from Detroit to Paris, airline attendant and Italian interpreter Anna Mari Barile sang the United States National Anthem over the loudspeaker while other passengers stood as a sign of respect, The Daily Mail reported.

The veterans were heading to France on Monday, and at least one was on his way to Omaha Beach to mark the 70th anniversary of D-Day coming up on Friday, June 6.

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After learning that the men had served in the military, and at the encouragement of fellow airline employees, Barile began singing a rendition of The Star Spangled Banner.

Another interpreter told WXYZ-TV, "Everybody in the boarding area had tears in their eyes."

Passenger Alyssa Vermeulen, on her way to Italy via Paris for her honeymoon, filmed the scene on her phone and uploaded it to YouTube.

"I was worried that something had happened, but when I asked my husband, he said that we had several WWII veterans on the plane," Vermeulen told TODAY.com. "Shortly after, the flag appeared out of the gate and everyone stood for the national anthem.

"It was a lovely display of patriotism in such a crazy place," she said. "Usually, airports are a high stress environment where people are rushing to connections, frantically gathering items, or anxiously waiting (for) their zone call to board, but for a few minutes everyone in the airport was standing, quiet and peaceful, showing respect to those who fought for our freedom."

Vermeulen was touched by the tribute. She told TODAY that her grandfather served as a Marine in World War II.

She said everyone stopped to thank the men for their service on the plane. The pilot thanked them all by name, and announced when the plane was flying over Normandy.

"It truly was beautiful," she said, "and it made the long plane ride, that would usually be filled with complaints of small bathrooms and uncomfortable seats take on a whole new meaning of gratitude for what we are so lucky to have."

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