美国有线新闻 CNN 墨西哥发生8.1级地震 美国各地举行9·11纪念活动（在线收听）

AZUZ: Moving to another coast now. Rescuers are scouring homes in southern Mexico. They're looking for survivors after a tremendous earthquake struck about 74 miles offshore on Thursday night. With a magnitude of 8.1, the tremor was capable of destroying entire towns.

On average, the world only sees about one quake this powerful every year. Mexico hasn't had a tremor like this for a century. It struck an impoverished area. There were multiple aftershocks. And government officials say it killed dozens of people. Many in the region were asleep when the quake struck near midnight.

It was felt hundreds of miles away, in places like Mexico City, in Guatemala City, and it generated a tsunami, a massive ocean wave that measured almost six feet in one area. Mexico's military and police are helping the search for survivors and distribution of medical supplies.

Memorial ceremonies are being held across America today, 16 years after the worst terrorist attack in U.S. history. Americans are honoring the thousands who were killed and the police, firefighters and other rescuers who died trying to save them.

The assault was carried out by the al Qaeda terrorist group, a radical Islamic organization based in Afghanistan and Pakistan. Nineteen al Qaeda members hijacked four U.S. passenger planes on September 11, 2001. They crashed two of the planes into the Twin Towers, the skyscraper that formed the World Trade Center in New York City, both of the massive buildings collapse soon afterward.

A third plane was crashed in Washington, D.C. It hit the Pentagon. The headquarters of the U.S. Defense Department and a fourth flight crashed into a field near Shanksville, Pennsylvania, reportedly after its passengers and crew tried to take back control of the plane.

Two thousand nine hundred and seventy-seven people were killed in the September 11th attacks, and just over a week later, U.S. President George W. Bush declared a war on terror.

The southeast Asian country of Afghanistan was giving al Qaeda a place to live and train at that time. And on October 7, 2001, after Afghanistan's Taliban rulers refused to turn over al Qaeda's leader to the United States, America led attacks against targets in Afghanistan. The conflict there continues today.