(CNN) -- Chileans gathered in a candlelight vigil early Sunday morning to commemorate the one-year anniversary of the 8.8-magnitude earthquake that killed 521 people and left thousands homeless in the South American nation.

President Sebastian Pinera was among those attending the vigil in the coastal town of Cobquecura, the epicenter of last year's quake.

A bugler played "Taps" after a moment of silence at 3:34 a.m. -- the exact time when the quake struck.

"I remember that morning as if it were today," Pinera told the crowd of mourners, describing the quake as "the most destructive in the history of our country."

The president, who was weeks away from taking office when the quake struck, recalled his experience visiting the most devastated parts of the country -- hearing screams of anguish of people trapped beneath tons of cement and seeing dazed victims wandering the streets in search of water.

Pinera said dozens remained missing a year after the quake, and said more than 2 million people in the country were "directly and personally affected" by the quake and ensuing tsunami.

"We are all aware that there are still many countrymen who remain victims of this earthquake and this tsunami," Pinera said.

After the vigil, he told CNN Chile that the country had completed "a little more than half" of the reconstruction required after the massive quake destroyed 220,000 homes, thousands of schools and hundreds of hospitals.

"That is a gigantic accomplishment for all Chileans," he said.

He told CNN Chile that about 70,000 homes had been rebuilt or were under construction, and pledged that all victims who lost their homes would have a permanent place to stay before the beginning of winter 2012.

At the vigil, Pinera closed his remarks by leading the crowd in singing the country's national anthem, and called on Chileans to unite across political boundaries to continue rebuilding efforts "stone by stone and brick by brick."

Additional memorial events were scheduled throughout the day Sunday.