Santiago, Chile (CNN) --
More than 2 million people were affected by a massive 8.8-magnitude earthquake that rocked Chile early Saturday, President Michelle Bachelet said in a televised news conference.
At least least 214 people were killed in the quake and the resulting tsunami, which ravaged parts of the Chilean coast and fanned out across the Pacific Ocean.
A large wave killed three people and 10 were missing on the island of Juan Fernandez, 400 miles (643 km) off the coast of Chile, said Provincial Governor Ivan De La Maza.
On mainland Chile, the task of trying to save survivors and recover the dead was fully under way. Buildings lay in rubble, bridges and highway overpasses were toppled and roads buckled like rumpled paper. Mangled cars were strewn on several highways, many of the vehicles coming to rest on their roofs.
"This is a major event. This happened near some very populated areas," said Randy Baldwin, a geophysicist with the U.S. Geological Survey. "With an 8.8 you expect damage to the population in the area."
As the day unfolded, desperate relatives searched for missing loved ones. Many of the survivors took to the Internet to ask for help in locating relatives.
"I'm from Colombia and I'm searching for my aunt," said one person on Twitter.
The quake struck at 3:34 a.m. (1:34 a.m. ET) off the Pacific coast at a depth of nearly 22 miles (35 km) and about 60 miles (100 km) northwest of Chillan, Chile, the USGS said. Santiago, the capital, is 200 miles (325 km) northeast of the epicenter.
At least 33 aftershocks were reported, including a 6.3-magnitude in Argentina.
"There are really aftershocks like every hour," said Felipe Baytelman, speaking to CNN from Santiago.
Chilean officials took to the airwaves to try to control any jitters.
"We are asking everyone to stay calm, to be patient," Chilean President Michelle Bachelet told reporters after inspecting some of the damaged areas. "We assure everyone that emergency crews are working to resolve these issues."
Bachelet declared areas of catastrophe, similar to a state of emergency, which will allow her to rush in aid. She said the town of Chillan -- which was destroyed by a killer quake in 1939 -- was one of the worst affected.
Bachelet noted that two of the largest hospitals had suffered structural damage and patients were taken to other facilities. Other public institutions also were affected.
The military was coordinating the transfer of patients to hospitals, said Undersecretary of Public Health Jeanette Vega. "All patients are being cared for," she told reporters in the city of Concepcion.
But she pleaded for anyone who did not need immediate medical care not to seek treatment. "This is a time when we need to be in solidarity with the people who need it most," she said, also asking for any health workers able to pitch in to do so.
Four field hospitals were being set up and tanker trucks full of fresh water were already circulating in areas that had lost access to clean water, she said.
Other public institutions also were affected. "There were reports of riots at one of the jails," Bachelet said. "The jails have, of course, received significant damage. The justice department is looking into the situation, evaluating the damage. We are looking into possibly moving some of these inmates."
The president also asked Chileans to help each other.
"We are looking into shelters," she said. "We are looking into other people providing room in their homes."
In Washington, Chilean ambassador Jose Goni said Chile could manage the catastrophe.
"Eventually, after deeper examination, the government may decide it needs support in some areas," he told CNN.
The United States has resources positioned to assist if Chile requests help, President Obama said in a midafternoon address to the nation.
Obama also warned residents in Hawaii and other areas that could be affected by a tsunami to heed safety instructions from state and local officials.
A tsunami warning for Hawaii was lifted Saturday afternoon. Waves of 3 feet were recorded at the city of Hilo on the Big Island of Hawaii, but were lower than expected, and no damage was reported.
Meanwhile, tsunami activity was reported on the island of Tasmania, according to officials in Australia.
Saturday's temblor comes about six weeks after an 7.0-magnitude earthquake devastated parts of Haiti and killed more than 220,000 people. The Chilean quake, at magnitude 8.8, was 700 to 800 times stronger.
Coastal Chile has a history of deadly earthquakes, with 13 quakes of magnitude 7.0 or higher since 1973, the USGS said. As a result, experts noted that newer buildings are constructed to help withstand the shocks.
President-elect Sebastian Pinera, who will take office in March, also was monitoring the situation and warned, "The number of victims could get higher."
The capital lost electricity and basic services, including water and telephones. Bachelet said regional hospitals had suffered damage; some were evacuated. A major bridge connecting northern and southern Chile was rendered inoperable, and the Santiago airport was shut down for at least the next 24 hours.
Chilean television showed buildings in tatters in Concepcion, in coastal central Chile. Whole sides of buildings were torn off, and at least two structures were engulfed in flames. Video showed roads that were destroyed and impassable.
The earth's rumbling was felt by millions in Chile and in parts of Argentina as well. Some buildings were evacuated in the Argentine capital, Buenos Aires, which is 690 miles (1,111 kilometers) away from Santiago.
In Hawaii, the U.S. Coast Guard closed all commercial ports in the Hawaiian islands to incoming traffic and was encouraging vessels to evacuate to sea. All recreational boaters were asked to take immediate precautions and avoid the water.
In addition, four of 10 U.S. military ships in port in Hawaii were heading out to sea. One ship in San Diego got under way because of high seas.
California and Alaska were under a tsunami advisory.
But evacuations of coastal areas began at 6 a.m. (11 a.m. ET). Outdoor siren systems in each Hawaiian county sounded simultaneously to alert residents and visitors to evacuate coastal areas, and U.S. Air Force planes equipped with loudspeakers flew over more remote areas to issue warnings.
CNN Chile, CNN's partner network, suffered damage to its broadcast facilities but continued operating.
Eduardo de Canto, the head of airport operations in Santiago, told Chile's TVN that the terminal in the airport is severely damaged although he said runways were operational.
Santiago resident Leo Perioto jumped out of his bed in his apartment at the top of a six-story building.
"The whole building was shaking," he said. "The windows were wobbling a lot. We could feel the walls moving from side to side."
Glass shattered at the Santiago Marriott Hotel, but there appeared to be no structural damage, said Alessandro Perez.
Anita Herrera at the Hotel Kennedy in Santiago said electricity was out and guests were nervous.
"Our hotel is built for this," she said. "In Chile, this happens many times."
The U.S. State Department said all but two U.S. Embassy personnel in Chile were accounted for.
Secretary of State Hillary Clinton said she will proceed Sunday with her planned trip to five Latin American countries, including Chile.
Saturday's epicenter was just a few miles north of the largest earthquake recorded in the world: a magnitude 9.5 quake in May 1960 that killed 1,655 and unleashed a tsunami that crossed the Pacific.