CHRISTCHURCH – Residents in coastal areas of New Zealand fled through the night Monday after a powerful 7.8 earthquake struck just after midnight, triggering a potentially “destructive” tsunami. The earthquake, centered north of Christchurch on the South Island, was felt throughout the country, causing widespread damage but there were no reports of serious injuries. As tsunami warning sirens were activated in South Island coastal towns and along the east coast of the North Island, police and emergency workers went door-to-door to evacuate seaside properties. A “destructive tsunami” with waves up to five metres (16 feet) was possible, the ministry of civil defence, responsible for emergency management in New Zealand, said in a bulletin. Some early waves were up to two-metres but civil defence warned they could intensify and described the tsunami as “an event of life-threatening or national significance”. The earthquake struck at 12:02am Monday (1102 GMT Sunday) and was 23 kilometres deep, the US Geological Survey said putting the epicentre near the alpine tourist village of Hanmer and the rural township of Cheviot in North Canterbury. It was one of the most powerful shakes to rock earthquake-prone New Zealand and ignited painful memories for residents in Christchurch which was