TALCA, Chile (February 28, 2010)--Authorities believe at least 700 people are dead after one of the largest earthquakes ever recorded tore apart houses, bridges and highways Saturday in the central part of Chile, the head of Chile's emergency agency said.

The magnitude-8.8 quake was felt as far away as Sao Paulo in Brazil, 1,800 miles to the east.

Baylor University-hosted seismograph stations near Abilene and Lake Whitney both recorded the 8.8 earthquake Saturday.

The full extent of damage remained unclear Sunday as dozens of aftershocks shuddered across the disaster-prone Andean nation.

Chilean President Michelle Bachelet declared a "state of catastrophe" in central Chile.

Although the official estimate says at least 214 people are dead, Carmen Fernandez, head of the National Emergency Agency, said, "We think the real figure tops 300. And we believe this will continue to grow."

Chile's president says 1.5 million people were affected by the quake, and officials in her administration say 500,000 homes were severely damaged.

The Pacific Tsunami Warning Center in Hawaii has lifted its Pacific-wide tsunami alert issued after the deadly earthquake.

The center issued a warning for 53 countries and regions in the area immediately after the magnitude-8.8 quake hit.

It lifted the warning Sunday after small waves were reported as far away as Japan and Russia.

There were no reports of significant damage or injuries.

A tsunami advisory was canceled in the last U.S. area that had been under any sort of alert after the Chilean earthquake.

The Alaska Tsunami Warning Center canceled the advisory early Sunday morning for the far reaches of the Aleutian Islands, stretching from Sand Point to Attu in the west.

Much earlier Saturday, a tsunami warning for Hawaii was canceled after just small waves hit the islands.

U.S. coastal areas stretching from the southern California to Alaska's Aleutians along with Canada's British Columbia were under an advisory, which is the lowest level alert.

That advisory was lifted in segments throughout the day.

No injuries or significant property damage were reported in mainland coastal areas, where waves packed little punch and often amounted to no more than surges or rough surf.

According to the center, among the areas with the highest waves was Santa Barbara, Calif., where waves were at nearly three feet and King Cove, Alaska at two feet.

Most places noted by the center had waves of around a foot or less.

The earthquake struck Saturday 56 miles northeast of the city of Concepcion at a depth of 22 miles, the U.S. Geological Survey said.

Concepcion, which is one of the largest cities in Chile, has a population of around 670,000, according to a 2002 census.

An earthquake of magnitude 8 or stronger can cause "tremendous damage," the USGS said.

The quake that devastated Haiti's capital Port-au-Prince on Jan. 12 had a magnitude of 7.0.

In the town of Talca, just 65 miles from the epicenter of the quake, Associated Press journalist Roberto Candia said it felt as if a giant had grabbed him and shaken him.

The town's historic center largely collapsed.

Neighbors pulled at least five people from the rubble.

The U.S. Geological Survey said there were two-dozen aftershocks of magnitude 5 or greater and one of 6.9.

Presidential press secretary Robert Gibbs said the White House is monitoring the situation, including the potential for a tsunami.

Gibbs also said U.S. stands ready to help the Chilean people "in this hour of need."

State Department spokeswoman Megan Mattson said the U.S. sends its "heartfelt condolences and prayers for the residents of Chile."

Mattson says she has no immediate information about the welfare of Americans visiting or living in the country.

She did say that all the 118 employees of the U.S. Embassy are accounted for.

The Defense Department said it hasn't received requests yet to help with any relief effort.

U.S. Southern Command, based in Miami, oversees the U.S. military presence in South American.

Sgt. Santita Mitchell of the command's public affairs office says the command is monitoring the situation.