A youth and his sister were burnt to death when a fire broke out at their house in east Delhi following a blast in a refrigerator compressor on Friday, Delhi Fire Service said.Kamal,18, and Geeta, 23, suffered severe burn injuries in the fire incident reported from Jafrabad around 3.45 p.m. "Both were rushed to a nearby hospital where Kamal was declared brought dead. His sister succumbed to her burn injuries during treatment," a fire official said. The official said three fire tenders took half an hour to douse the flames.