Luke Bryan and his wife, Caroline, are once again dealing with a family tragedy.

Bryan reached out to his fans on Tuesday to thank them for their prayers after his infant niece, Sadie Brett Boyer, died. Sadie Brett is the daughter of Caroline’s brother, Bo Boyer, and his wife, Ellen. She was born last summer with cardiac issues.

"We thank all of you for your prayers. Love y'all," Bryan tweeted.

NEWS: Luke Byran Is 'Honored' to Be Raising His Late Sister's Children

Bryan's sister-in-law gave updates on the child on her Facebook page, and on Monday, shared that her daughter "declined overnight." Sadie Brett was being treated at a hospital for health issues, including an infection that affected her liver.

"Please flood the heavens with prayers," Ellen wrote on Monday. "We will not give up on our tough, brave Brett."

Unfortunately, this isn't the first time the 40-year-old country superstar has dealt with a family tragedy. Bryan's brother, Chris, was killed in a car accident in 1995 at the age of 26. His sister, Kelly, also died in 2007 at her home of undetermined causes. She was 39 years old.

And following the unexpected death of his brother-in-law, Ben Lee Cheshire, in November 2014, the 40-year-old country superstar took in his teenage nephew -- Kelly's son, Til -- to live with him and his wife, as well as their two sons, Bo and Tatum.

WATCH: Luke Bryan Talks Raising His Nephew in a 'Crazy Household'

"My only siblings gone from the world in a flash, in two different, crazy, tragic manners," Bryan told ABC News in 2013, about losing both his brother and sister.

"Losing my brother changed me tremendously and losing Kelly, even more," he also told People Country in 2014. "I literally do not take one second for granted."

Watch below: