Volcanoes have wreaked havoc around the world for eons. While some eruptions posed no threat to humans, others have leveled cities, killed thousands and nearly decimated entire populations. But what eruptions were the worst?
Click through for a countdown of the deadliest volcanic eruptions in recorded history.
Pictured, an ash cloud from the eruption of Anak Krakatau volcano on May 19, 2008, in Sunda Strait, Java, Indonesia.
10. Mount Papandayan, Indonesia, 1772
Death toll: 2,900
When Papandayan erupted in 1772 in West Java, Indonesia, a huge chunk of the mountainside collapsed, causing a devastating landslide. The avalanche of volcanic debris destroyed no fewer than 40 villages around the volcano. About 2,900 people were killed.
Pictured, smoke billows from Mount Papandayan on Nov. 15, 2002.
9. Mount Vesuvius, Italy, 79 A.D.
Death toll: 3,360-16,000
Vesuvius erupted in 79 A.D., shooting a column of ash 20 miles into the air. Super fast-moving streams of gas, rock and pumice called pyroclastic flows charged down the mountainside, obliterating everything in their path. The cities of Pompei, Herculaneum and Stabiae were wiped out completely. At least 3,360 people -- maybe as many as 16,000 -- were killed.
Centuries later in 1631, Vesuvius had another major eruption, killing between 3,000 and 4,000.
It wasn't until the 18th century that Pompei, Herculaneum and Stabiae were once again exposed.
8. Mount Galunggung, Indonesia, 1822
Death toll: 4,000
An active stratovolcano on the west side of the island of Java, Galunggung erupted in 1882, sending mudslides of volcanic matter called lahars pouring down the mountainside. In all, more than 4,000 people were killed.
Pictured, Galunggung erupted again in 1982.
7. Kelud, Indonesia, 1919
Death toll: 5,000
When Kelud erupted in East Java, Indonesia, in May 1919, it spewed boiling water out from the crater lake at its summit. The water rushed down the side of the volcano, mixing with mud, sediment and other material. The lethal flow inundated more than 11.5 square miles of the surrounding countryside and killed more than 5,000 people.
6. Laki, Iceland, 1783
Death toll: 10,000
Laki's eruption began on June 8, 1783, and lasted for nine months. The volcano, located in southern Iceland, expelled three cubic miles of lava and blasted 100 million tons of sulfur dioxide and toxic gases into the atmosphere. A poisonous fog enveloped Iceland, destroying the country's soil and vegetation. Nearly three-quarters of Iceland's livestock was killed as a result, and in the two years following the eruption, one-fifth of Iceland's population -- 10,000 people -- died, largely from starvation.
Laki's eruption was 100 times larger than the 2010 Eyjafjallajokull event that produced a massive ash cloud and resulted in the grounding of tens of thousands of international flights.
5. Mount Unzen, Japan, 1792
Death toll: 15,000
Mount Unzen is actually a group of several active stratovolcanoes in western Kyushu, Japan. When Unzen erupted in 1792, it was accompanied by a large earthquake that triggered the collapse of one of the volcano's lava domes. The massive landslide killed an estimated 5,000 people and caused a giant tsunami that resulted in 10,000 more deaths.
At left, a massive flow of lava, molten rocks and ash from Mount Unzen raises huge clouds of ash and hot gas on June 8, 1991.
4. Nevado del Ruiz, Colombia, 1985
Death toll: 25,000
When the Colombian volcano erupted in November 1985, it generated four thick lahars. These fatal landslides of rock, pumice, mud and water rushed down the mountainside at up to 37 mph. One lahar tore through the town of Armero, located in a valley at the base of the volcano, and killed three-quarters of the town's residents. Three other towns were hit by the volcano's debris. In all, roughly 25,000 people were killed.
3. Mount Pelee, Martinique, 1902
Death toll: 30,000
The 1902 eruption of Mount Pelee, located on the Caribbean Island of Martinique, obliterated the town of St. Pierre and killed about 30,000 people, all in less than five minutes. Although tremors, mudslides and minor eruptions signaled danger in the days preceding Pelee's eruption, few evacuated St. Pierre. Those that did were replaced by refugees from the surrounding countryside.
When the volcano blew on the morning of May 8, deadly pyroclastic flows streamed down the mountain, incinerating the nearby city. Only three people are reported to have survived the event, the most famous of which was a prisoner who had been locked in a poorly ventilated jail cell underground.
2. Krakatoa, Indonesia, 1883
Death toll: 36,000
When Krakatoa erupted in the summer of 1883, the sound of its explosion could be heard across one-third of the surface of the Earth, and one of the resultant tsunamis caused a ripple as far away as the English Channel.
On Aug. 26, the eruption began. As the island released a 17-mile-high column of black ash, the earth began to shake, generating a tsunami. Krakatoa roared through the night, and the next day, the volcano spewed its final, monumental explosion.
As Krakatau's magma chamber emptied, the sea filled its void, and the 2,600-foot-high volcanic cone fell in on its center. Nearly the entire island collapsed underwater, resulting in an enormous tsunami and 100-foot tidal waves that decimated villages on surrounding islands. More than 36,000 people were killed.
Today, a new volcano has risen in Krakatoa's place. Called Anak Krakatau, or "child of Krakatau," the volcano grows about five inches each week.
Next: What Would Happen If You Fell Into a Volcano?
1. Mount Tambora, Indonesia, 1815
Death toll: 90,000
The worst volcanic eruption in recorded history occurred in 1815 on the Indonesian island of Sumbawa, and was four times more powerful than the 1883 eruption at Krakatoa. Mount Tambora exploded on April 10, spewing three columns of fire and launching a plume of smoke and gas 26.5 miles high. Lava flowed down the mountain's slope at 100 mph all the way to the sea 25 miles away. Ash, dust and rocks rained down on the area for weeks. An estimated 90,000 people were killed on Sumbawa and neighboring islands. The eruption's effects were felt worldwide.
The explosion spurred global climate change. Huge amounts of sulfurous gas, ash and dust permeated the atmosphere, blocking sunlight, cooling the Earth and ushering in the infamous "year without a summer." The drastic cold weather -- the Northern U.S. saw extreme frost and heavy snowfall well into August -- destroyed crops around the world and led to the worst famine of the 19th century.