Watch Southwest Airlines crew serenade special needs birthday girl

What is it about viral videos of Southwest Airlines flight attendants that makes us so happy? First, there was the rapping flight attendant David Holmes, who entertained passengers with his safety instructions. Then there was the comedienne Marty Cobb, whose safety routine were so funny she was featured on The Ellen DeDeneres Show.

The latest video is a heart-warming example of how an airline can really make a difference — and make a little girl smile.

On a recent flight from Tampa to Pittsburgh, 4-year-old Mazzy Marzona, who has spina bifida, was returning home from a vacation with her family. It also happened to be Mazzy’s birthday. Her sister Birkly suggested that their mother let the crew know, in the hopes that they would give Mazzy an airline pin.

Little did they know what the flight attendants had in store.

The crew made a birthday cake out of toilet paper and a crown out of pretzel bags. Just before landing, the crew asked everyone on the plane to shut their windows and serenade little Mazzy with a rendition of “Happy Birthday” that will bring tears to your eyes.

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Mazzy’s mother was overwhelmed with gratitude, writing on her Facebook page, “'Thank you Southwest for giving our special girl such a special day!! I said [that] was that the coolest thing and she said ‘ever in mine whole life!’“

This article originally appeared on Yahoo Travel.