The singer reached out to thank fans for prayers after little Sadie Brett died on Tuesday (21Feb17) following a battle with a liver infection.

Sadie was the daughter of Luke's wife Caroline's sister, Ellen Boyer.

The little girl had been dealing with heart and internal issues since birth.

Her mum asked followers on Facebook for prayers on Sunday night (19Feb17), writing: "Please flood the heavens with prayers. We will not give up on our tough, brave Brett."

The country star adopted his late sister's youngest child following the death of his brother-in-law in 2014.

The singer cancelled a string of shows and appearances after 46-year-old Ben Lee Cheshire passed away, seven years after his wife Kelly - Bryan's only sister - died unexpectedly, aged 39.

The couple left behind three teenage children and the That's My Kind of Night hitmaker has informally adopted the Cheshires' youngest kid, 13-year-old Til, who has moved from Georgia to live with the Bryans in Nashville, Tennessee.