"Lord of the Dance" and "Riverdance" star Michael Flatley has announced the death of his wife, Niamh O'Brien.

Oct. 6 (UPI) -- Lord of the Dance and Riverdance star Michael Flatley has announced the death of his wife, Niamh O'Brien.

"My heart is broken. I have lost my beautiful wife, Niamh, and my best friend," Flatley wrote on Instagram Monday, without offering details about the cause of her death.

"My gorgeous bride of twenty years has gone to the Lord in Heaven. She was the most loving mother, wife and person, and our lives will never be the same without her. Thank you for all the love and kindness you have shown us. Please keep Niamh, Michael St. James, and our family in your thoughts and prayers."

The couple married in Ireland in 2006 and welcomed son Michael St. James Flatley in 2007.