SANTIAGO, Chile — Authorities lifted tsunami warnings for Chile’s long coastline early Wednesday after a magnitude-8.2 earthquake struck the South American nation north. 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.

President Michelle Bachelet flew to the region to review damage in daylight after declaring a state of emergency and sending a military plane with 100 anti-riot police to join 300 soldiers who were deployed to prevent looting and round up escaped prisoners.

Thousands of people evacuated from low-lying areas were returning home after a spending a long night outside due to the threat of a tsunami.

Seawater flooded city streets and washed away some fishing boats in Iquique, but by early Wednesday no major tsunami damage was apparent. Chile’s entire coast was initially subject to the mandatory evacuation order, which lasted nearly 10 hours in coastal communities closest to the offshore epicenter.

The shaking that began at 8:46 p.m. Tuesday also touched off landslides that blocked roads, knocked out power for thousands, damaged an airport and started fires that destroyed several businesses. Some homes made of adobe were destroyed in Arica, another city close to the quake’s offshore epicenter.

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.

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 captured early Wednesday.

Bachelet, who just returned to the presidency three weeks ago, waited five hours after the quake struck to address her nation. 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,” Bachelet tweeted after Tuesday night’s temblor.