SANTIAGO, Feb 27 (Reuters) - A huge magnitude-8.8 earthquake struck Chile early on Saturday, killing at least 122 people, knocking down homes and hospitals, and triggering a tsunami that rolled menacingly across the Pacific.
TV Chile reported that a 15-storey building collapsed in the hardest-hit city of Concepcion, where buildings caught fire, major highway bridges collapsed and cracks opened up in the streets. Cars turned upside down lay scattered across one damaged bridge.
Residents huddled in streets full of rubble of masonry and glass from destroyed homes. Many were terrified by powerful aftershocks and desperately trying to call friends and family.
Chilean President-elect Sebastian Pinera said 122 people had been killed and the death toll could climb higher.
Tsunami warnings were posted around the Pacific, including the U.S. state of Hawaii, Japan and Russia.
Telephone and power lines were down in much of central Chile, making it difficult to assess the full extent of the damage close to the epicenter.
Chile is the world's No. 1 copper producer, and the quake halted operations at two major mines.
"Never in my life have I experienced a quake like this, it's like the end of the world," one man told local television from the city of Temuco, where the quake damaged homes and forced staff to evacuate the regional hospital.
The U.S. Geological Survey said the earthquake struck 70 miles (115 km) northeast of Concepcion at a depth of 22 miles (35 km) at 3:34 a.m. (0634 GMT).
The capital Santiago, about 200 miles (320 km) north of the epicenter, was also badly hit. The international airport was closed for at least 24 hours as the quake destroyed passenger walkways and shook glass out of doors and windows.
Chile's Codelco, the world's largest copper producer, suspended operations at its El Teniente and Andina mines, but reported no major damage and said it expected the mines to be up and running in the "coming hours."
Production was halted at the Los Bronces and El Soldado copper mines, owned by Anglo American Plc (AAL.L), but Chile's biggest copper mine, Escondida, was operating normally.
Chile produces about 34 percent of world supply of copper, which is used in electronics, cars and refrigerators.
President Michelle Bachelet said a huge wave hit the Juan Fernandez islands. Radio stations reported serious damage on the archipelago, where Scottish sailor Alexander Selkirk was marooned in the 18th Century inspiring the novel Robinson Crusoe.
Bachelet, who flew over the worst-affected area, said residents were also being evacuated from coastal areas of Chile's remote Easter Island, a popular tourist destination in the Pacific famous for its towering Moai stone statues.
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 tsunami was pretty big too. We reported some places around 8 feet. And it's quite possible it would be higher in other areas," he added.
An earthquake of magnitude 8 or over can cause "tremendous damage," the USGS says. The Jan. 12 quake that devastated Haiti's capital Port-au-Prince was measured as magnitude 7.0.
Bachelet urged people to stay calm and to remain at home to avoid road accidents. "With a quake of this size we undoubtedly can't rule out more deaths and probably injuries," she said.
Local television showed a building in flames in Concepcion, one of Chile's largest cities with around 670,000 inhabitants. Some residents looted pharmacies and a collapsed grains silo, hauling off bags of wheat, television images showed.
Broken glass and chunks of concrete and brick were strewn across roads and several strong aftershocks rattled jittery residents in the hours after the initial quake.
In the moments after the quake, people streamed onto the streets of the Chilean capital hugging each other and crying.
"My house is completely destroyed, everything fell over ... it has been totally destroyed. Me and wife huddled in a corner and after hours they rescued us," said one elderly man in central Santiago.
There were blackouts in parts of Santiago. Emergency officials said buildings in the historic quarters of two southern cities had been badly damaged and local radio said three hospitals had partially collapsed.
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.
Saturday's quake shook buildings as far away as Argentina's Andean provinces of Mendoza and San Juan. A series of strong aftershocks rocked Chile's coastal region from Valdivia in the south to Valparaiso, about 500 miles (800 km) to the north.
The United Nations and the White House said they were closely monitoring the situation in Chile and the potential threat of tsunamis in the Pacific.
A State Department official said Secretary of State Hillary Clinton was being kept apprised of the situation in Chile, which she is due to visit on Tuesday on a Latin American tour.