Granger Smith's 3-year-old son River Kelly Smith's cause of death was confirmed by his representative late Thursday.
Smith shared the sad news on his social media pages, alongside a photo of himself with his youngest son.
"I have to deliver unthinkable news. We've lost our youngest son, River Kelly Smith. Following a tragic accident, and despite doctor's best efforts, he was unable to be revived," Smith wrote.
He continued, "Amber and I made the decision to say our last goodbyes and donate his organs so that other children will be given a second chance at life. Our family is devastated and heartbroken, but we take solace in knowing he is with his Heavenly Father."
Smith went on to call River "special," something everyone who met him knew instantly.
"The joy he brought to our lives cannot be expressed and his light will be forever in our hearts. If there are words to say more, I cannot find them in this moment. Love the ones close to you. There has never been a more difficult moment for us than this," Smith wrote.
Smith also asked fans to donate to the hospital where River was treated, the Dell Children's Medical Center of Central Texas, instead of sending flowers.
"The doctors, nurses and staff have been incredible," Smith wrote at the end of his message.
Smith and his wife, Amber Emily Bartlett, have two other children, daughter London, 7, and son Lincoln, 5.
After Smith shared the news, several of his country music colleagues offered their prayers and condolences.
"I can't image what y'all are going thru. Praying for u and ur family brother. We are heartbroken for u guys," Jason Aldean wrote.
According to the Centers for Disease Control and Prevention, drowning is the fifth leading cause of unintentional injury death in the U.S. About one in five deaths from drowning are children 14 and younger.
The American Red Cross suggests making sure home pools are secured with appropriate barriers; make sure someone is watching young children in the water and always within arm's reach; install anti-entrapment drain covers and safety release systems to help children against getting trapped by a drain; and to check water first if a child goes missing. For more pool and safety tips, click here.
Photo credit: Instagram/Granger Smith