A powerful earthquake that rocked New Zealand on Monday triggered landslides and a small tsunami, cracked apart roads and homes and left two people dead, but largely spared the country the devastation it saw five years ago when a deadly earthquake struck the same region.

Strong aftershocks continued to shake the country on Monday, rattling the nerves of exhausted residents, many of whom had spent a sleepless night huddled outside after fleeing for higher ground to avoid the tsunami waves.

The magnitude 7.8 earthquake struck the South Island just after midnight in a mostly rural area that’s dotted with small towns. Near the epicenter, it opened up snaking fissures in roads and sparked landslides.

The quake caused damage in Wellington, the capital, more than 200 kilometers (120 miles) to the north. It was also strongly felt to the south in the city of Christchurch, which was devastated by an earthquake in 2011 that killed 185 people. Residents said the shaking went on for about three minutes.

Police said one person died in the small coastal town of Kaikoura and another in Mt. Lyford, a nearby ski resort. Several other people had reportedly suffered minor injuries in Kaikoura, police spokeswoman Rachel Purdom said.

Prime Minister John Key flew over the destruction in Kaikoura by helicopter on Monday afternoon, as aftershocks kicked up dust from the landslides below. Cars could be seen lying on their sides and parts of the road were clearly impassable.

“It’s just utter devastation. ... That’s months of work,” Key told acting Civil Defence Minister Gerry Brownlee as they hovered above the damage. Key and Brownlee estimated the clean-up would cost hundreds of millions of dollars and clearing the debris and blocked roads could take months. 

Defense force personnel were planning to take food, water and other supplies to Kaikoura on Tuesday.

The prime minister said waves of about 2 meters (6.6 feet) hit the coast but the tsunami threat had since been downgraded to coastal warnings.

He said authorities had no reason to believe the death toll would rise above the two reported fatalities.

“On the very best information we have at the moment, we think it’s only likely to be two. But of course there are isolated parts of the country which we don’t have perfect eyes on, so we can’t be 100 percent sure,” he said.

Key said officials had decided not to declare a national emergency because the nation’s regions were able to adequately cope with the situation.

The quake completely cut off road access to Kaikoura, said resident Terry Thompson, who added that electricity and most phones were also down in the town of 2,000, a popular destination for tourists taking part in whale-watching expeditions.

Thompson was out of town but managed to reach his wife by cellphone during the night before her phone died.

“She said the glass exploded right out of the double ranch-slider,” he said. “The neighbor’s chimney was gone, there were breakages and things smashed everywhere.”

His wife helped a 93-year-old neighbor and a tourist into her car and drove to higher ground, he said.

“They stayed in the car all night but couldn’t sleep,” Thompson said. “They’re all very, very tired and concerned about the state of their property.”

The main road to Kaikoura was blocked in places by landslides, and police were working to airlift out a few tourists stranded in their campervans to the north and south of the town, according to emergency services officials in the nearby Marlborough region.

Kaikoura suffered “major infrastructure damage” in the quake, the Marlborough Emergency Management Group said in a statement. Sewage and water supplies were knocked out, though power was gradually being restored Monday afternoon. Police were in radio communication with the town and mobile phone service was expected to be restored shortly.

The quake temporarily knocked out New Zealand’s emergency call number, 111, police reported. In Wellington, it collapsed a ferry loading ramp, broke windows and caused items to fall from shelves. It also forced hundreds of tourists onto the streets as hotels were evacuated.

Australians Paul and Sandra Wardrop and their children Alexander, 15, and William, 12, were on the 10th floor of the Park Hotel when the shaking began.

“We felt that the building was going to collapse,” Sandra Wardrop said. “You could hear the sounds of the building shaking and see cracks appearing in the walls, in the plasterwork in the bedroom.”

The family was among dozens of people who took shelter in the capital’s parliamentary complex, which threw open its doors. It was William’s 12th birthday, and while he didn’t get to tour Wellington as planned, he did get to meet Key, who visited the displaced tourists.

New Zealand, with a population of 4.7 million, sits on the “Ring of Fire,” an arc of seismic faults around the Pacific Ocean where earthquakes are common.

Monday’s quake brought back memories of the magnitude 6.3 earthquake that struck Christchurch in 2011 and destroyed much of the downtown area. That quake was one of New Zealand’s worst disasters, causing an estimated $25 billion in damage.

Monday’s quake was stronger but its epicenter was deeper and much farther from major urban areas. Location, depth and other factors beyond magnitude all contribute to the destructive power of an earthquake.

The location of Monday’s quake largely helps explain why the damage was so minimal compared to the 2011 temblor, said Mark Quigley, associate professor of active tectonics at the University of Melbourne in Australia. The 2011 quake was located almost directly beneath Christchurch, meaning tens of thousands of people were exposed to the most violent shaking at the epicenter. Monday’s quake was centered in a rural area that is home to just a few thousand people.

The 2011 quake also had a tremendous amount of high frequency energy, including very strong vertical ground motions which felt “like you’re being picked up by a giant and being shaken around,” Quigley said.

But for those in Christchurch on Monday, the shaking felt very different _ more of a rolling motion. “They were far enough away that a lot of that high frequency energy was dissipated,” he said.

Authorities in Wellington told people who work in the city’s central business district to stay home on Monday. Officials said some large buildings were showing signs of structural stress, and the quake would likely have caused a mess in some buildings. The city’s suburban rail network was shut while crews checked tracks, bridges and tunnels.

New Zealand’s Ministry of Civil Defence and Emergency Management reported that a tsunami wave struck at about 1:50 a.m. and warned residents living in low-lying areas anywhere along the country’s east coast to move to higher ground.

There was confusion about the tsunami threat throughout the morning. The ministry initially said there was no threat but later wrote on Twitter “situation has changed - tsunami is possible” before reporting that a tsunami had hit.

The quake was centered 93 kilometers (57 miles) northeast of Christchurch, according to the US Geological Survey. The USGS initially estimated it had a magnitude of 7.4 before revising it to 7.8. It said the quake struck at a depth of 23 kilometers (14 miles), after initially putting the depth at 10 kilometers (six miles). Earthquakes tend to be more strongly felt on the surface when they are shallow. (AP)