Country singer Hank Williams Jr's daughter dies aged 27 following car accident

The daughter of Grammy award-winning country singer Hank Williams Jr has died following a fatal car accident.

Katherine Williams-Dunning and her husband, Tyler Dunning, were travelling in their SUV down a highway in Tennessee on June 13 when their vehicle, which was towing a boat, crossed a median strip and flipped over.

A spokesperson told Us Weekly that the couple were taken to Vanderbilt University Medical Center in Nashville. While 29-year-old Tyler's condition is not yet known, Katherine later died. She was 27 years old. 

Katherine was the daughter of 71-year-old Williams Jr. and Mary Jane Thomas. The couple also share a 23-year-old son, Samuel, who had asked fans to "pray so hard" for his sister and brother-in-law following the "terrible accident" on Saturday.

But on June 14 (US time), Katherine's older half-sister, singer-songwriter Holly Williams, announced her death on Instagram as she shared the final photo the family took together.

"I have no words. On Friday morning I talked the family into taking this picture and had no idea it would be our last together with my precious little sister Katie," Holly began in her post. "We all went to my great aunt's funeral on Thursday whom we all loved dearly, and now are faced with another one. ALL we need is prayers. My daddy. My little brother. Katie's husband (he is awake and responding don't know injury extent yet). My niece and nephew. Her Mama. The Dunning family. All of us. So. Many. Prayers. Jesus is close. Thank you all."

"Be merciful to me, O LORD, for I am in distress; my eyes grow weak with sorrow, my soul and my body with grief. Psalm 31:9," added Holly, who is Williams Jr's daughter with his second wife, Becky White.

Katherine leaves behind two children she shares with Tyler: five-year-old son Beau and two-year-old daughter Audrey Jane. She had owned the clothing company Weston Jane, named after her children.