"Chimneys and walls crumbled to the ground, roads cracked in half and residents were knocked off their feet as a powerful magnitude-7.1 earthquake rocked New Zealand's South Island early Saturday. The prime minister said it was a miracle no one was killed. Only two serious injuries were reported from the quake, which shook thousands of people awake when it struck at 4:35 a.m. near the southern city of Christchurch. There were reports of some people trapped inside damaged buildings — though none appeared to be crushed by rubble — and a few looters broke into some damaged shops in the city of 400,000, officials said. Power was cut across the region, roads were blocked by debris, and gas and water supplies were disrupted, Christchurch Mayor Bob Parker said. Chimneys and walls of older buildings were reduced to rubble, and Parker warned that continuing aftershocks could cause masonry to fall from damaged buildings. ""We're all feeling scared — we've just had some significant aftershocks,"" he told TV One News. ""Tonight we're just people in the face of a massive natural disaster, trying to help each other ... and we're grateful we haven't lost a life."" State geological agency GNS Science reported 29 aftershocks in the 14 hours following the quake, ranging in strength from magnitude 3.7 to 5.4."