Thousands of earthquakes happen every day around the world. Most are hardly felt, if at all. But sometimes pieces of Earth's crust suddenly slip past each other in a massive release of pent-up stress. The jolted Earth rumbles, buildings collapse, streets buckle, and thousands of people die. These movements are nature's most violent act and take a grim toll on human life and infrastructure.
The deadliest earthquake in recorded history rattled the Shensi province of China on Jan. 23, 1556, and killed an estimated 830,000 people. The death toll was particularly high among peasants who lived in artificial caves that were dug into soft rock and collapsed during the quake. This picture shows a pagoda whose peaked top was lost in the shaking. Earthquake damage is also visible on the corners. Click on the "Next" label to learn about 11 more deadly quakes.
? John Roach, msnbc.com contributor
1906: The Great Quake
The California earthquake of April 18, 1906, ranks as the most deadly in U.S. history: About 3,000 people perished. The Great Quake, as the event is known, was estimated at magnitude 7.9 and ruptured along 296 miles of the northernmost section of the San Andreas fault. Broken gas lines, fractured chimneys and toppled chemical trucks sparked a series of fires that torched large sections of San Francisco, as seen in this image taken from Golden Gate Park.
1964: Good Friday?
The most powerful earthquake in North American history shook the state of Alaska on March 27, 1964, the Friday before Easter. The magnitude-9.2 temblor triggered a tsunami that was responsible for 113 of the 128 deaths associated with the earthquake, according to the U.S. Geological Survey. The giant waves struck along the West Coast down to California, and rolled across the Pacific to Hawaii. This image shows the coastal town of Seward, Alaska, in the wake of the tsunami.
1970: Mountains moved
The magnitude-7.9 earthquake that struck just off the west coast of Peru on May 31, 1970, reduced the coastal towns of Casma and Chimbote to rubble and killed at least 3,000 people. Even greater disaster struck the towns of Yungay and Ranranhirca. The shaking sent an avalanche of mud, rock and ice down the slopes of the Cordillera Blanca and buried the cities under tens of feet of debris. An estimated 70,000 lives were lost. Here, a statue of Christ is all that remains in Yungay.
1976: Chinese region flattened
The deadliest earthquake in modern times flattened the industrial city of Tangshan, China, in the early morning of July 28, 1976. The Chinese government put the death toll at 255,000, though many geologists believe it was much higher ? up to 655,000. Nearly 800,000 more were injured. Tremors and damage from the magnitude-7.5 quake extended as far as Beijing, about 90 miles from the epicenter. Here, a few tents and temporary shelters are visible amid the debris.
1985: Mexico shaken
On Sept. 19, 1985, a magnitude-8.2 earthquake off Mexico's Pacific coast wreaked the greatest havoc in Mexico City, about 220 miles from the epicenter. There, hundreds of buildings were toppled, and thousands of people died. Government officials put the death toll at about 9,000, though other sources say it may have been as high as 35,000. A triggered tsunami sent waves rising almost 10 feet crashing into the coastal towns of Lazaro Cardenas, Zihuatanejo and Manzanillo. Here, a 21-story steel-constructed building in Mexico City lies in ruins.
1995: Tremors hit Japan
More than 6,400 people died in the aftermath of a magnitude-6.8 earthquake that hit Japan on Jan. 17, 1995. Most of those deaths occurred in Kobe, the city closest to the epicenter. Many buildings suffered partial collapse, such as the one shown in this picture. Total damage was estimated at more than $100 billion.
2003: Iranian city crumbles
On Dec. 26, 2003, a magnitude-6.6 earthquake crumpled the adobe city of Bam, Iran, killing an estimated 30,000 people. About 60 percent of the city's buildings were destroyed and nearly all the rest were damaged. The event ranks as the deadliest in Iran's history. Here, one of the victims is carried to the grave.
2004: The Asian tsunami
On Dec. 26, 2004, a magnitude-9.1 earthquake ruptured the ocean floor off the west coast of Sumatra, Indonesia, and triggered a series of destructive tsunamis that killed at least 225,000 people in 11 countries. Millions more were stripped of their homes. Scientists estimate the energy released in the event was more than 1,500 times the power of the atomic bomb dropped on Hiroshima in 1945. Here, villagers walk through a devastated area of Pangdandaran on the Indonesian island of Java.
2005: Landslides in Kashmir
At least 86,000 people were killed when a magnitude-7.6 earthquake hit the Kashmir region of northern Pakistan on Oct. 8, 2005. Millions more were left homeless at the outset of the harsh Himalayan winter. Landslides swept away villages and blocked roads for relief and rescue workers, worsening the human toll. At least 1,350 people were killed in neighboring India, and the shaking was also felt in Afghanistan. Here, rescue workers dig through the rubble looking for survivors at a school in Balakot, Pakistan.
2008: Catastrophe in China
An estimated 70,000 people died and millions were left homeless when a magnitude-7.9 earthquake hit a region north of Sichuan's provincial capital, Chengdu, on May 12, 2008. Tremors were felt as far away as Beijing and Shanghai. One of the most tragic episodes was the collapse of a high school in Juyuan. This picture shows searchers digging through the school's rubble.
2010: Huge setback for Haiti
Extreme poverty and extremely poor construction standards contributed to the devastation and death in Haiti when a magnitude-7.0 quake hit Port-au-Prince and its surroundings on Jan. 12, 2010. The death toll amounted to more than 230,000, and aid officials say it will take years for Haiti to recover fully ... if it ever can. This picture shows rescuers carrying one of the injured away from the rubble.
