Rolling aftershocks battered Chile nearly every hour today after an earthquake rocked the country early this morning.
The death toll from the quake climbed throughout the day, and by evening the national emergency office was saying at least 300 people had died in the disaster.
U.S. officials have been unable to reach at least three Americans working with the U.S. Embassy in Chile.
The quake also triggered tsunami warnings in areas as far away as the western coast of the United States, Hawaii and Japan.
Chilean President Michelle Bachelet said that though central Chile was devastated by the earthquake she has not requested international assistance.
"The system is functioning," she said. "People remain calm. We're doing everything we can with all the forces we have."
The U.S. Embassy estimates up to 1,000 American citizens are in the most affected area, but said no American casualties or injuries have been reported. Chile's minister of housing said in an interview on Chilean TV that about 1.5 million houses have been damaged by the earthquake and 500,000 houses are severely damaged.
The earthquake, which hit just after 3 a.m. local time, was 500 times larger than the one that devastated Haiti last month but was much deeper, likely making the number of casualties far fewer than those in the Caribbean nation.
The Chile earthquake struck 22 miles below the surface in the Bío Bío region of the country, while the Haiti earthquake struck only 6 miles below the surface, according to scientists with the U.S. Geological Survey.
The three-minute-long quake struck less than 100 miles north from the southwest coastal city of Concepcion -- the second-largest city in Chile with a population of 670,000 -- but caused damage as far away as the capital Santiago, nearly 200 miles away.
To read all of ABC's coverage on the Chile Earthquake, click here.
A 15-story building collapsed in the city of Concepcion. Television reports from Concepcion showed some residents looting pharmacies and a collapsed grain silo, hauling off bags of wheat, according to reporting by Reuters.
A bridge over the Claro River, located in the Maule region, has also collapsed.
Hospitals in the area have been evacuated, and the airport in Santiago has been shut down for 24 hours due to damage in the terminal, Chilean officials said. Phone lines and power are also out of service in some areas making it difficult to assess the death toll. Meanwhile, the country has been coping with at least 13 aftershocks measuring a magnitude of 5.0 or stronger.
Chilean television has reported that businesses will be closed Monday and Tuesday, and schools will not reopen till March 8.
Carol Urban, an official at the U.S. Embassy in Santiago who has been stationed there for three years, described the earthquake as "long and scary."
"But Chile is in a seismic zone, so the Chileans as well as the Americans at the embassy are always somewhat prepared but this was certainly a surprise to us," she said.
Finding Americans in Chile Earthquake
The U.S. Embassy in Chile is reaching out to any American residents or tourists. For those concerned about family and friends in Chile, visit the State Department Web site at www.state.gov. U.S. citizens can also can call the U.S. State Department number 888-407-4747 to register a name of a loved one.
White House press secretary Robert Gibbs said in a statement, "We are closely monitoring the situation, including the potential for a tsunami. Our thoughts and prayers are with the people of Chile, and we stand ready to help in this hour of need."
In Hawaii, officials ordered evacuations of beaches and low-lying areas, but when the waves arrived, there were no reports of injuries or major damage. Tsunami warnings have also been issued for Japan and Russia.
Eyewitnesses Recount Horror of Chile Earthquake
Ronald Scott, an American who was staying at a hostel in Santiago when the earthquake hit, told ABC News that while he was terrified, the damage he has witnessed was far less extensive than what he saw reported from Haiti.
"It was very scary," Scott said. "The first thing I did was jump underneath the first table I could find and even that was about to collapse on me.
"I also grabbed a bottle of water just in case I was going to be there for awhile. The first thought I had was what was going on in Haiti and what they must have gone through," he said.
"Everything just started jumping up and down, the lights went out and everything sounded like a railroad train," Scott said. "The buildings were shaking, but they're still standing because of the construction."
The buildings in Chile are constructed specifically to withstand earthquakes, and the country is no stranger to disaster from an unexpected quake.
Chile has the record for the world's strongest earthquake -- a 9.5-magnitude quake that struck in 1960. The current 8.8-magnitude quake will likely make the top 10 for world records.
Chilean officials are asking people to stay in their houses if their homes are not damaged and to stay off the roads unless there is an emergency.
"Everything is still standing," Scott said. "The only things that are not broken were not nailed down in the house."
Elliot Yamin, a former contestant on "American Idol," had just finished performing at a music festival in Vina Del Mar, Chile, when he said the "rumbling started.
"At first, it was more of a kind of swaying back and forth, and then it was a really fast kind of shaking," Yamin said.
In a sixth-floor hotel room, Yamin said he quickly moved to a doorway and then the hallway, and eventually got out of the building safely. Still, Yamin said he feared for his life.
Former 'American Idol' Contestant Describes the Earthquake
"I thought it was a [6.0 magnitude or a 7.0 magnitude]; I had no idea it was an 8.8," Yamin said. "The shaking and rumbling was just so -- I didn't know if I would make it down the stairs.
"It was surreal. People were panicking and a couple of pregnant women in the hospital were crying," he said. "I shed a few tears. I was pretty emotional."
Yamin said the chaos has mostly died down hours after the earthquake rocked the country at 3 a..m. local time and that the aftershocks have become far less frequent.
ABC News' Nancy Ayala contributed to this report.