Authorities in New Zealand reported 75 confirmed dead and as many as 300 people missing on Wednesday in the wake of Tuesday's 6.3-magnitude earthquake in the city of Christchurch.

Police declared a nighttime curfew in the downtown area, asking residents to remain in their homes, as rescue crews worked to reach any remaining survivors.

See a special AP Interactive on the aftermath of the earthquake in New Zealand. 

One woman, Ann Bodkin, was pulled to safety after being trapped for 24 hours in the twisted wreckage from Tuesday's quake.  Beams of sunlight reportedly broke through the city's drizzly weather as she emerged from the rubble. 

"The sun came out the moment she was removed from the building," Christchurch Mayor Bob Parker said. "It was like God turned on the lights."

Authorities believe as many as 100 people may be buried under the debris inside the Canterbury TV building. 

Prime Minister John Key declared a state of emergency for the largest city located on the South Island of New Zealand.  It is the country's second-largest urban area.

"There is incredible carnage right throughout the city," Superintendent Gibson told Radio New Zealand. "There are bodies littering the streets.  They are trapped in cars and crushed under rubble where they are clearly deceased. Our focus has turned on the living."

Hundreds of military personnel, police and rescue teams - including specialists from the U.S. -  are in route to the devastated city. 

According to the U.S. Geological Survey, Tuesday's quake was part of the "aftershock sequence from the 7.1-magnitude temblor that struck the country on Sept. 4."

"It's a nightmare. A lot of people were just getting back on their feet after the original quake," said Kevin Fenaughty, data center manager for GNS Science, an earth-science research institute.