Churches, homes, hospitals were toppled while roads and bridges were upended by the monstrous quake - the 7th largest in world history--which was centered near the southern city of Concepcion. The quake rattled the entire country and was also felt as far away as Argentina, Brazil and Venezuela.

For hours the only reliable and voluminous stream of news out of Chile was provided by social networks, primarily Twitter users with #Chile and #terremotochile.

Santiago's airport and subway system was temporarily closed and operations were shuttered at two of Chile's largest copper mines. Panicked Chileans fled into the streets and spent the night sleeping on lawns and mattresses.

One 15 floor building in Concepcion collapsed from which 18 people were rescued. In the capital of Santiago, one of the city's oldest Catholic churches was severely damaged.

The quake unleashed a tsunami which produced a high surf in several Chilean seaside communities, reaching as high as 7-9 feet. The Chilean island of Juan Fernandez was hit by an "enormous wave," according to Bachelet. Local officials said the wave came half way through the island's small, central town. There's no information on damage inflicted on the island.

On Saturday afternoon, Hawaii was bracing for a tsunami of unpredictable proportions. But an official with the Pacific Tsunami Warning Center said the waves were smaller than expected and Coast Guard crews found no major damage to ports or waterways. 

The Pacific Tsunami Warning Center issued a Pacific-wide tsunami warning for countries in Latin America, and as far away as the U.S. state of Hawaii as well as Japan, Russia, Philippines, Indonesia and the South Pacific. French Polynesia was also put on alert. "Chile probably got the brunt force of the tsunami already. So probably the worst has already happened in Chile," said Victor Sardina, geophysicist at the warning center.

The final toll on human and material damage is still being assessed as rescue crews fan out across the country.

Saturday's quake in Chile was as much as 50 times more powerful than the killer quake in Haiti earlier this year that took tens of thousands of lives.

The U.S. government has told Chile it is ready to offer whatever help is requested.

There were some scattered reports of looting in several Chilean cities but no major social chaos has been reported. Much of the electrical and communication grid went down and is slowly being restored. Blackouts darkened most of Santiago immediately after the quake. Communication from the most affected region in the southern part of the country is still spotty.

In 1960, Chile was hit by the world's biggest earthquake since records dating back to 1900. The 9.5 magnitude quake devastated the south-central city of Valdivia, killing 1,655 people and sending a tsunami which battered Easter Island 2,300 miles (3,700 km) off Chile's Pacific seaboard and continued as far as Hawaii, Japan and the Philippines.

Chileans living abroad and thousands of others around the world tuned into Web-based Chilean TV broadcasts to follow events.