ROSWELL, Ga. — The daughter of late singer and entertainer Whitney Houston was found unresponsive, face down in a bathtub Saturday and taken to a hospital in the north Atlanta suburbs, police said.Bobbi Kristina Brown was found by her husband, Nick Gordon, and a friend. The friend called 911 while her husband performed CPR on Brown because they did not believe she was breathing nor had a pulse, said Officer Lisa Holland, a spokeswoman for the Roswell Police Department. When police arrived, they gave Brown additional care until she was taken alive to North Fulton Hospital. A hospital spokeswoman did not return repeated messages seeking comment on Brown’s condition. “Right now she’s still alive at the hospital,” Holland said.Detectives were still at the home Saturday afternoon trying to determine what occurred.Police were called to the home Jan. 23 for a report of a fight, Holland said. When officers arrived, they found no one there.Brown, 21, is the only child of Houston and R&B singer Bobby Brown. A representative for the family did not immediately return messages seeking comment.Whitney Houston was found dead in a hotel bathtub on Feb. 11, 2012, in Beverly Hills, California. The 48-year-old Houston had struggled for years with cocaine, marijuana and pills, and her behavior had become erratic. Authorities examining Houston’s death found a dozen prescription drug bottles in the hotel suite. They concluded that Houston accidentally drowned. Heart disease and cocaine use were listed as contributing factors in Houston’s death.