Authorities lifted tsunami warnings for Chile's long coastline early on Wednesday after a magnitude 8.2 earthquake struck the South American nation's northern coast.
Six people were crushed to death or suffered fatal heart attacks, a remarkably low toll for such a powerful shift in the Earth's crust.
The extent of damage from Tuesday night's quake could not be fully assessed before daybreak, president Michelle Bachelet said.
She declared a state of emergency in the region and sent a military plane with 100 anti-riot police to join 300 soldiers deployed to prevent looting and round up escaped prisoners.
Thousands of people were evacuated from low-lying areas but most began to return home as the tsunami alerts were gradually lifted in Chile's long coast.
The shaking touched off landslides that blocked roads, knocked out power for thousands, damaged an airport and provoked fires that destroyed several businesses.
About 300 inmates escaped from a women's prison in the city of Iquique, forcing the closure of the border with Peru. Officials said some two dozen had been recaptured early on Wednesday.
In Arica, another city close to the quake's offshore epicentre, hospitals treated minor injuries, and some homes made of adobe were destroyed, authorities said.
Mining in Chile, which is the world's top copper-producing nation, was not affected, although world prices for the red metal jumped as the quake raised supply concerns because most of the Chilean mining industry is in the northern regions.
Chile's Navy lifted tsunami warnings for all of Chile long coastline at around 7am local time (11am GMT).
The mandatory evacuation orders had remained in effect until nearly dawn for coastal areas north of Antofagasta, a decision backed by the Pacific Tsunami Warning Centre in Hawaii, regarding the coastline of Chile as still dangerous.
Ms Bachelet, who just returned to the presidency three weeks ago, spoke well after midnight, five hours after the quake struck, and she flew to quake-hit regions on Wednesday morning to assess the damage.
It was not lost on many Chileans that 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.
Most of the 500 dead from that magnitude-8.8 tremor survived the shaking, only to be caught in killer waves in a disaster that destroyed 220,000 homes and washed away large parts of many coastal communities.
"The country has done a good job of confronting the emergency. I call on everyone to stay calm and follow the authorities' instructions," Ms Bachelet tweeted after Tuesday night's temblor.
When she finally addressed the nation, she said her interior minister would monitor the tsunami threat throughout the night and co-ordinate the emergency response.
"Classes have been suspended and we will be able to know the extent of the damage in the light of day," she added.
The tsunami warning centre initially had cancelled tsunami watches for areas other than northern Chile and southern Peru.
The only US impact might be higher waves Wednesday for Hawaii's swimmers and surfers, it said.
The U.S. Geological Survey initially reported the quake at 8.0, but later upgraded the magnitude of the quake that struck 61 miles northwest of Iquique.
More than 20 significant aftershocks followed, including a 6.2 tremor. More aftershocks and even a larger quake could not be ruled out, said seismologist Mario Pardo at the University of Chile.