Former "American Idol" contestant David Oliver Willis (Season 13) is paying tribute to the victims of the Pulse nightclub shooting with a song.

>> Click here to watch him perform the song

“There’s 50 cars left in the parking lot,” his song, performed at a vigil, begins. “There’s mothers waiting at the door / There’s 50 mothers waiting at the door.”

>> Read more about the Orlando nightclub shooting

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"I had my guitar in my car and I just got back from a gig. And leaving there I just kept thinking about it throughout the day," Willis told Fusion. "A lot of people are focused on what happened, which is terrible and tragic. But at the end of the day when this stuff is over and the vigils are done, there's still 50 homes that are broken."