Nearly a million residents were forced to evacuate after a magnitude-8.2 earthquake struck off Chile's northern coast, triggering a small tsunami.
Six people are confirmed dead, Chilean Interior Minister Rodrigo Penailillo said. Many of the victims died from heart attacks or falling debris.
The extent of the damage from Tuesday night's quake couldn't be fully assessed before daybreak, President Michelle Bachelet said, but she wasn't taking any chances, declaring a state of emergency for the northern part of the country and deploying armed forces to prevent looting. Military officials are also rounding up prisoners who escaped from a women's prison in the city of Iquique. Officials said 39 of the 300 prisoners who escaped have been recaptured.
More than 900,000 people and 11 hospitals were evacuated along the Chilean coastline, government officials said.
Tsunami warnings have been canceled.
The quake, which struck 6 miles beneath the ocean floor and 61 miles west-northwest of Iquique, triggered landslides that blocked roads, knocked out power for thousands, damaged an airport and provoked fires that destroyed several businesses. In Arica, another city close to the quake's offshore epicenter, hospitals treated minor injuries, and some homes made of adobe were destroyed, authorities said.
The earthquake was so strong that the shaking it caused in La Paz, Bolivia, 290 miles from the epicenter, was the equivalent of a 4.5-magnitude tremor, authorities there said. The quake triggered at least eight strong aftershocks in the first few hours, including a 6.2 tremor.
PHOTOS: Powerful Earthquake Hits Chile
Bachelet's government extended its tsunami warnings for northernmost Chile long after they were lifted elsewhere. Its mandatory evacuation orders remained in effect until nearly dawn for coastal areas north of Antofogasta, a decision backed by the Pacific Tsunami Warning Center in Hawaii.
"We regard the coast line of Chile as still dangerous, so we're maintaining the warning," geophysicist Gerard Fryer said.
The currents should reach Hawaii at about 3:30 a.m. local time (9:30 a.m. ET today), Fryer said.
"All of our models are suggesting that it will be strong enough to generate significant currents. And therefore we are advising people to stay off the beach, stay out of the water," he said.
Bachelet, who just returned to the presidency three weeks ago, spoke well after midnight, five hours after the quake struck. The last time she presided over a major quake, days before the end of her 2006-10 term, her emergency preparedness office prematurely waved off a tsunami danger, with 500 people dying.
"The country has done a good job of confronting the emergency. I call on everyone to stay calm and follow the authorities' instructions," Bachelet tweeted after Tuesday night's temblor.
Chile is one of the world's most earthquake-prone countries because the Nazca tectonic plate plunges just off the coast beneath the South American plate, pushing the towering Andes cordillera to ever-higher altitudes.