A video (below) featuring a 4-year-old boy in Texas singing to his baby sister in heaven is touching the hearts of many nationwide.
In May 2017, Alex's 4-month-old sister Ava Lynn died from hydronephrosis, a condition that affects the kidneys, reports KTRK.
So on what would have been Ava's first birthday, Alex decided to pay tribute to his little sister with his guitar and the song, "Remember Me" from the animated movie "Coco."
Alex moved many to tears after singing heartbreaking lyrics like "though I have to travel far, remember me. For even if I'm far away, I hold you in my heart" to his sister.
His father tweeted the clip on Dec. 30.
"He's only 4 years old and he understands," he wrote. "He didn't even know he was being recorded. He just wanted to sing to her for her 1st birthday!"
The video quickly went viral, being liked by more than 140,000 people and re-tweeted by over 55,000 in five days.
"The movie made me cry but this made me cry even more," tweeted one person in response. "He's a wonderful wonderful older brother."
"Damn bro, I vowed not to shed a tear in 2018," added another. "And here we are first day of the new year and my eyes couldn’t hold back."
"This is a boy who will grow up to be an outstanding man and make a difference in this world," wrote a third.
The family says they were deeply touched and shocked by the attention Alex's clip received.
"My wife and were literally brought to tears seeing how much love Alex and Ava and our family has received," wrote the child's father. "We were FLOORED last night!! I couldn't me more thankful. Thank you to everyone from our little family! What a 1st birthday baby girl! All Glory to God #StayHumble"
It's not the first time a video highlighting the love between siblings has captured the nation's attention, reports ABC News.
Earlier in December, a 2-year-old boy in Indiana warmed hearts when he attempted to "save" his 5-year-old sister, Ruby Lewis, from a wrestling competition.
Believing she was in an actual fight, Ruby's 2-year-old brother, Jash, rushed onto the mat and attempted to rescue his sister.
A video of the incident was later posted on Facebook by the mother of Ruby's opponent, who wrote, "When the girl you're wrestling has a tough little brother, don't mess with his sister."