Arturo Garcia Rojon clearly remembers the day 13 years ago when the world came crashing down around his ears.

At 7:20 a.m. on Sept. 19, 1985, as an earthquake rumbled through Mexico City, a 10-floor apartment block collapsed like a house of cards on top of his double-story home while he was shaving, burying Garcia and his wife under tons of rubble, bricks and dust. But the Garcias were lucky, they survived. At least 7,000 other residents of the Mexican capital did not.

Yet, like 18 million other residents of one of the world's biggest metropolises, the Garcias still live in Mexico City, where a repeat of the 1985 earthquake is virtually guaranteed. The only question is how destructive it will be and how many people will die next time.

Every year, at least 1,000 earthquakes, most of them so small that people do not notice them, ripple through Mexico. So far this century, there have been up to 40 major quakes. In the Pacific off Michoacan state, the oceanic Cocos tectonic plate is being pushed under the continental North American tectonic plate, producing enormous forces that at times result in abrupt and potentially devastating movements.

Japan's Meteorological Agency estimates nearly 10 percent of the energy released worldwide by earthquakes each year is concentrated in and around the string of islands that make up the nation of Japan. Major cities such as Tokyo and most recently Kobe have been flattened this century in quakes that have killed tens of thousands.

Japan is literally crisscrossed with fault zones, rips in the Earth's surface caused by quake activity. The Fossa Magna fault runs roughly north to south through most of the country while another fault zone roughly runs east to west through the main islands of Honshu and Kyushu. Although the entire nation is vulnerable to quakes, the possibility of a quake that could wipe out the heavily populated Tokyo area causes the most anxiety.

CIUDAD SANDINO, Nicaragua--Maria Corina Artola has never been wealthy or even financially comfortable. But now she is the poorest she has ever been. Little by little over the years, she had established herself as a street vendor, earning enough to support her four children in a shack along an open sewer. That was until tropical storm Mitch washed it all away.

Standing dazed before a few sticks of wood and plastic sheets donated by the Managua city government, Artola tried to figure out how to make a shanty that would shelter her family. "All that I could rescue were my children because they are the most precious thing I have," she said.

Artola's tragedy underscores the plight of millions of people left homeless by Mitch and symbolizes the overall predicament of the tiny, poor countries of Central America where they live. "Suddenly, in two weeks, we have lost what it took 50 years to build," said Javier Ibisate, dean of economics at the University of Central America in San Salvador.

In Nicaragua, seven new bridges built with $20 million in Japanese aid had been inaugurated in the past three years. All of them survived, but this country must now replace 80 other bridges destroyed or damaged by Mitch.

Honduran officials estimate that their development efforts have been set back 30 years. El Salvador, Guatemala and Belize suffered relatively few deaths and less damage than Honduras and Nicaragua. Panama and Costa Rica largely escaped damage.

Mitch, the fourth-largest hurricane to hit the Caribbean, will go down in the record books as the most destructive storm since the Great Storm of 1780 killed 20,000 people. One U.N relief official termed Mitch the worst natural disaster in Latin America in a century.

The rains and flooding also have come close to extinguishing the hope that the region would finally begin to recover from the devastating civil wars of the 1980s. "As we say in El Salvador, it has rained on what was already wet," Ibisate said. "There was so much destruction from the wars, and we had just begun to rebuild bridges and roads."

In a reminder of the days when wars spilled across the region's borders, land mines have floated up in the flood waters along the Honduras-Nicaragua frontier, presenting new dangers.

The 1997-1998 El Niņo phenomenon is responsible for the deaths of 21,706 in 27 countries, and caused $33 billion dollars in damage, the World Meteorological Organization said. The figures are contained in a new report compiled by 450 weather experts from all over the world who met in Ecuador. The number of injured and people physically affected by El Niņo reached 117,862,114. Nearly five million people were displaced and homeless because of the weather event. Its aftermath, La Niņa, was most recently felt in the form of Hurricane Mitch, which killed 9,550 with many more still missing.

Scientists say this year's record-setting El Nino demonstrates that the cost of natural disasters is rising, both in terms of financial costs and human lives, despite improvements in risk forecasting, AP said. More people in the United States and other nations are living in harms' way, they said, and are only beginning to seriously consider what might happen if a severe storm, drought, fire or other catastrophe swept through their area. At the same time, researchers said people have become dependent on technologies and public infastructures that tend to get knocked out during disasters and are increasingly vulnerable.

Climatologists, geologists and social scientists discussed the impacts of natural disasters and the shortcomings of predictions Tuesday in special sessions at the meeting of the American Geophysical Union. In 1998, the Worldwatch Institute estimates that the world's economy has suffered $97 billion in losses from natural disasters. The death toll so far is 35,000; 320,000 people lost their homes.

A scientific team that visited the site of the July 17 tsunami on the Papua New Guinea coast now theorizes that the deadly sea waves were probably the result of an undersea landslide caused by an earthquake centered inland. The death toll exceeds 3,000, including hundreds of people whose bodies have not been recovered, making it probably the deadliest tsunami of the 20th century.

The scientists noted that the topography on the New Guinea coast--where the ocean floor drops rapidly close to shore--is similar to that found in coastal areas throughout the world, including Southern California.

It thus is conceivable that a similar tsunami could strike the Los Angeles-Orange County metropolitan area, they said. Although no such huge wave has been reported in Southern California, small tsunami surges have come to shore.