The death of Alexandra "Sasha" McHale was announced by the team Sunday. No other details were released.
Kevin McHale has been on leave since Nov. 10 to deal with what the team called a personal family matter.
Team owner Leslie Alexander said in a statement that he extends his "deepest condolences" over the loss of the McHales' "beautiful daughter." He called Kevin and wife Lynn "loving and dedicated parents who will need our continued support throughout this very difficult time." He said the "entire organization is mourning."
Kelvin Sampson has been the interim coach. There is no timetable for Kevin McHale's return.