In the early hours of Christmas Day 1974, a tropical cyclone swept through Darwin... leaving an indelible mark on the city and its people. Severe Tropical Cyclone Tracy is regarded as one of the most significant cyclones in Australia's history. 66 people were killed and more than 600 injured. Around 8 out of 10 buildings were destroyed or seriously damaged... with a cleanup bill of more than four billion dollars in today's figures.SBS has spoken to survivors of Cyclone Tracy. They say 50 years on, the memory of Christmas 1974 is still raw.