premise: A 16-year-old girl was recovering in hospital Monday after seeing her sister and grandparents killed as their home was buried by a landslide, emergency authorities said.
  Raja Ram, 61, his wife Kala Wati, 56, and five-year-old granddaughter, Priya Bandana Lata, were buried when the corrugated iron house in the Fijian hillside village of Saweni was hit by the landslide that followed heavy rain on Saturday.
  They had just returned to the house from a family wedding, relatives told police.
  Priya's sister, 16-year-old Payal, probably owes her life to swift rescue effort from Constable Peni Verekauta who was on duty at the nearby Sawani police post when the landslide occurred.
  "I heard somebody screaming. When I located her she was half buried and a lemon tree had pinned her to the ground," said Verekauta, who freed the girl with the help of neighbours and an emergency unit which was called to the scene.
   What killed Priya and her grandparents?
hypothesis: their home was buried by a landslide