SAN ANTONIO — A San Antonio boy was caught on camera serenading his late baby sister for what would have been her first birthday.

San Antonio parents caught video of their 4-year-old son singing "Remember Me" from the movie, "Coco," to an altar dedicated to his sister, Ava.

“My son singing "Remember Me" from the movie "Coco" to his baby sister, Ava, who we lost this past May. He's only 4 years old and he understands. He didn't even know he was being recorded. He just wanted to sing to her for her 1st birthday! Happy Birthday mamas, we miss you,” Samir tweeted with the video.

Disney's "Coco" depicts the tradition of Dia de Los Muertos, a holiday celebrated around Halloween that honors/remembers the deaths of fallen ancestors.