SANTIAGO, Chile -- The death toll from a powerful 8.2-magnitude earthquake that struck off the coast of northern Chile rose to at least six Wednesday morning, the Chilean office of national emergency said.
Among the deaths are four men and a woman -- two who suffered heart attacks and three who were crushed in the late Tuesday quake, which triggered small landslides, caused power outages and generated a tsunami, officials said.
On Wednesday morning, Defense Minister Jorge Burgos described the government response as "satisfactory, on time and efficient." He said the military has been dispatched throughout the earthquake zone to ensure safety.
"Things are calm," he said.
But geologists say an even larger quake in the region could be lurking.
"This magnitude-8.2 is not the large earthquake that we were expecting in this area," said Mark Simons, a geophysicist at the California Institute of Technology in Pasadena. "We're expecting a potentially even larger earthquake."
It could be tomorrow. Or it could come in 50 years.
"We do not know when it's going to occur," he said.
Just after Tuesday's quake, about 300 prisoners escaped in the northern port city of Iquique, Interior Minister Rodrigo Penailillo said.
The quake struck around 8:46 p.m. local time, about 60 miles northwest of Iquique. It had a depth of 12.5 miles (20 kilometers), the U.S. Geological Survey said.
The Pacific Tsunami Warning Center issued several tsunami warnings but had canceled all of them by early Wednesday. Tsunami watches, which initially extended as far north as Mexico's Pacific Coast, were called off as well.
Tsunami waves more than 6 feet high generated by the earthquake washed ashore on the coast of Pisagua, said the center's Victor Sardino.
Iquique, with a population of more than 200,000, saw 7-foot waves.
An earthquake of the scale that struck Tuesday night is capable of causing tremendous damage. So if the initial reports stand, Chile may have dodged a major catastrophe.
Landslides damaged roads in some regions. Power and phone outages were reported in others.
Chile is on the so-called Ring of Fire, an arc of volcanoes and fault lines circling the Pacific Basin that is prone to frequent earthquakes and volcanic eruptions.
On March 16, a 6.7-magnitude earthquake struck about 37 miles (60 kilometers) west-northwest of Iquique. A 6.1-magnitude quake hit the same area a week later.
"The fact is, we will know the extent of the damage as time goes by and when we inspect the areas in the light of day," Chilean President Michelle Bachelet said early Wednesday. "The country has faced these first emergency hours very well."
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