Chile's president declared a state of catastrophe in the aftermath of a massive 8.8-magnitude earthquake Saturday that left bodies, crumbled buildings and outages in its wake.

The country's national emergency office said more than 300 people were dead, and the pre-dawn quake — the most powerful quake to hit the country in a half century — also cut electricity, water and phone lines to many outlying areas, meaning there was no immediate word of death or damage there.

The quake also unleashed a tsunami across the ocean, putting much of the Pacific Rim on alert for potentially devastating waves.

Hawaii Officials Evacuate Coastal Areas

Early Saturday, President Michele Bachelet, speaking at an emergency response center, appealed for Chileans to remain calm.

"Despite this, the system is functioning. People should remain calm. We're doing everything we can with all the forces we have. Any information we will share immediately," Bachelet said.

SLIDESHOW: First photos from Chilean quake

President-elect Sebastian Pinera said the earthquake caused serious damage to the country's infrastructure.

In the town of Talca, 65 miles from the quake's epicenter, its historic center, filled with buildings of adobe mud and straw, largely collapsed, though most of those were businesses that were not populated during the 3:34 a.m. quake. Neighbors pulled at least five people from the rubble while emergency workers, themselves disoriented, asked for information from reporters.

In the Chilean capital of Santiago, 200 miles northeast of the epicenter, a car dangled from a collapsed overpass, the national Fine Arts Museum was badly damaged and an apartment building's two-story parking lot pancaked, smashing about 50 cars whose alarms rang incessantly.

Santiago's airport will remain closed for at least 24 hours, airport director Eduardo del Canto said. The passenger terminal suffered major damage, he told Chilean television in a telephone interview. TV images show smashed windows, partially collapsed ceilings and pedestrian walkways destroyed.

The city's subway was shut as well, and hundreds of buses were trapped at a terminal by a damaged bridge, the transportation and telecommunications minister told Chilean TV. He urged Chileans to make phone calls or travel only when absolutely necessary.

The tsunami set off by the quake threatened every nation around the Pacific Ocean — roughly a quarter of the globe. Warnings were issued over a wide area, including South America, Hawaii, Australia and New Zealand, Japan, the Philippines, Russia and many Pacific islands.

The National Oceanic and Atmospheric Administration's tsunami warning monitors reported a wave measuring nearly eight feet hit near Talcahuano, Chile, about 90 minutes after the quake hit. Other waves of up to four feet hit other coastal areas. The NOAA has placed its alert on the highest level — severe.

A number of aftershocks continue to hit Chile, the largest one registering at magnitude 6.9, according to the U.S. Geological Survey.

Click for data from the USGS

U.S. State Department spokesman P.J. Crowley told Fox News that the embassy is reaching out to the Chilean government to offer assistance. He reported that the 100 personnel at the embassy are OK and accounted for.

"Chile has both significant capabilities and strong building codes. Second, the embassy has activated its warden system to communicate with Americans in Chile and make sure they are okay," Crowley said.

The quake epicenter was just 70 miles from Concepcion, Chile's second-largest city, where more than 200,000 people live along the Bio Bio river, and 60 miles from the ski town of Chillan, a gateway to Andean ski resorts that was destroyed in a 1939 earthquake.

In Santiago, modern buildings are built to withstand earthquakes, but many older ones were heavily damaged, including the Nuestra Senora de la Providencia church, whose bell tower collapsed.

In the coastal city of Vina del Mar, the earthquake struck just as people were leaving a disco, Julio Alvarez told Radio Cooperativa in Santiago. "It was very bad, people were screaming, some people were running, others appeared paralyzed. I was one of them."

Several hospitals have been evacuated due to earthquake damage, she said, and communications with the city of Concepcion remained down. She planned to tour the affected region as quickly as possible to get a better idea of the damage.

The largest earthquake ever recorded struck the same area of Chile on May 22, 1960. The magnitude-9.5 quake killed 1,655 people and left 2 million homeless. The tsunami that it caused killed people in Hawaii, Japan and the Philippines and caused damage to the west coast of the United States.

The Associated Press contributed to this report.