Three children died early Saturday in a fire which broke out at a farmhouse in northern Greece, authorities announced. The boys, aged 15, 7 and 5, got trapped inside the wooden house at a small village on the outskirts of the city of Kavala, while their three other siblings, their mother and grandparents survived. Experts investigating the cause of the shocking tragedy point to a wood stove used by the family. The blaze started as the family was asleep. Once the house begun to fill with smoke, the teenager rushed outside. But he realized that two of his younger brothers had stayed behind and returned to save them. Investigators believe that he lost consciousness and choked on the smoke, like his brothers, before the roof collapsed. Their mother and grandmother were slightly injured. According to local media, the mother, a teacher, was spending the weekend at the village with six of the family\'s 10 children, while the father was staying at their home in Kavala for work.