A powerful earthquake hit the New Zealand city of Christchurch on Tuesday, collapsing buildings, burying vehicles under debris and sending rescuers scrambling to help trapped people amid reports of multiple deaths.
Police said they were trying to confirm the early reports of multiple fatalities from the 6.3-magnitude quake, the second major temblor to strike the city since last September, while Prime Minister John Key told Parliament details still were too shaky to confirm deaths.
Witnesses said the quake destroyed the iconic stone Christchurch Cathedral, its spire toppled into a central city square, and there were reports of two buses crushed under falling buildings.
Live video footage showed parts of buildings collapsed into the streets, strewn with bricks and hattered concrete. Sidewalks and roads were cracked and split, and thousands of dazed, screaming and crying residents wandered through the streets as sirens blared.
Christchurch Mayor Bob Parker declared a state of emergency and ordered people to evacuate the city center.
"Make no mistake -- this is going to be a very black day for this shaken city," he said when asked about possible deaths.
The airport was closed and Christchurch Hospital was evacuated. Power and telephone lines were knocked out, and pipes burst, flooding the streets with water. Some cars apparently parked on the street were buried under rubble.
Some people were stuck in office towers and firefighters climbed ladders to pluck people trapped on roofs to safety.
"The details we have are extremely sketchy," the prime minister told Parliament. "The worrying fear, of course, is that this earthquake has taken place at a time when people were going about their business -- it is a very populated time, with people at work, children at school. Sadly, I cannot rule out that there have been fatalities.
"But we are aware of significant damage to buildings that had people in them at the time," he said.
Key said people were being told to get out of the city for their safety.
Other officials said there were unconfirmed reports of deaths from the earthquake.
New Zealand police said in a statement that there were reports of multiple fatalities in the city, including a report that two buses had been crushed by falling buildings. The police statement said there were other reports of fires burning in the city and people being trapped in buildings.
Gary Moore said he and 19 other colleagues were trapped in their twelfth floor office after the stairwell collapsed in the quake. He did not know if people on other floors were trapped.
"We watched the cathedral collapse out our window while we were holding onto the walls," Moore said. "Every aftershock sends us rushing under the desks. It's very unnerving but we can clearly see there are other priorities out the window. There has been a lot of damage and I guess people are attending to that before they come and get us."
The Pyne Gould Guinness Building, a multistory building containing more than 200 workers, has collapsed and an unknown number of people are trapped inside. Television pictures showed rescuers, many of them office workers, dragging severely injured people from the rubble. Many had blood streaming down their faces. Screams could be heard from those still trapped.
Parker, the mayor, said he was on the top floor of the city council building when the quake hit just before 1 p.m. local time, throwing him across the room.
"I got down onto the street and there were scenes of great confusion, a lot of very upset people," he said. "I know of people in our building who are injured and I've had some reports of serious injuries throughout the city."
The U.S. Geological Survey said the temblor was centered 3 miles (5 kilometers) from the city at a depth of 2.5 miles (4 kilometers). A 5.6-magnitude aftershock hit shortly after 7 miles (11 kilometers) east of the city at a depth of 3.7 miles (6 kilometers).
"When the shaking had stopped I looked out of the window, which gives a great view onto Christchurch, and there was just dust," said city councilman Barry Corbett, who was on one of the top floors of the city council building when the quake struck. "It was evident straight away that a lot of buildings had gone."
Christchurch has been hit by hundreds of aftershocks since a 7.1 magnitude earthquake struck Sept. 4 last year, causing extensive damage and a handful of injuries, but no deaths.
The city is home to about 350,000 people and is considered a tourist center and gateway to the South Island.
New Zealand sits on the Pacific "ring of fire" -- an arc of earthquake and volcanic zones stretching from Chile in South America through Alaska and down through the South Pacific. It records more than 14,000 earthquakes a year -- but only about 150 are felt by residents, and fewer than 10 a year do any damage.
The Sept. 4 quake wrecked hundreds of buildings in the city, and caused an estimated 4 billion New Zealand dollars ($3 billion) in damage. A strong aftershock in December caused further damage to buildings.
The city was still rebuilding from those quakes when Tuesday's temblor hit.