A 15-year-old girl was killed while visiting relatives for the weekend when someone approached a kitchen window in Calumet City and opened fire Sunday night, striking her and wounding one of her cousins, authorities said Monday. "We know what happened. We just don't know why,'' Calumet City police Chief Edward Gilmore said. Gilmore called the shooting of Ashaya Miller "a senseless killing" and said the girl does not appear to have been the target. A 19-year-old male cousin of Ashaya's also in the kitchen of her aunt's home was wounded in the elbow. Ashaya was shot about 9 p.m. in the 500 block of Ingraham Avenue in the south suburb, according to police and the Cook County medical examiner's office. She was taken to Advocate Christ Medical Center in Oak Lawn, where she was pronounced dead at 11:13 p.m. An autopsy Monday determined that Ashaya died of gunshots to the back, and her death was ruled a homicide, according to the medical examiner's office. Gilmore said the 19-year-old cousin lived in the home and Ashaya was visiting from Hammond, where she lived in the 1100 block of Truman Street. Responding officers found 10 people inside the home, including children. Food was being cooked on the stove, and fruit punch was being prepared. "It wasn't a party,'' the chief said. "It was normal living going on in this house at the time.'' Suddenly, three shots were fired from a gangway outside, piercing the kitchen window and hitting Ashaya and her cousin, the chief said. Shell casings were found outside, and the chief said the shooter apparently was tall enough — more than 6 feet — to reach the window. On Monday, officers with high-powered rifles and wearing SWAT gear executed a search warrant at a home nearby on State Street between Lincoln and Wentworth avenues, looking for evidence, Gilmore said. "It hurts,'' said Ashaya's grandfather, James Miller, 62, of south suburban Riverdale, who said he called Ashaya by her nickname, "Shay Shay.'' Miller said his grandson, the other victim, is doing better at the hospital after having surgery. Ashaya would come over to see her father, who lives in Riverdale with Miller, almost every weekend and sometimes even on her way home from school. Her school book bag and an extra pair of gym shoes were still at his house. She would often bring her homework and also enjoyed watching television and lounging on his couch, Miller said. "She was a good person. She was always over here to keep me company,'' Miller said. This weekend was no different, and he had seen her on Saturday, the day before the shooting. "She was in a good mood. She had gotten her nails done,'' Miller said. Ashaya was looking forward to seeing her friends and family at her aunt's home on Ingraham, where they had a party Saturday night, and she stayed overnight, her grandfather said. She had one brother, two sisters and many cousins, and other relatives with whom she was close. Miller had the day off from his bakery job and was at home when he was called to the hospital after learning Ashaya was shot. She had been in the kitchen as relatives were doing someone's hair.