1792day.year
A lava dome collapses on Mount Unzen, near the city of Shimbara on the Japanese island of Kyūshū, creating a deadly tsunami that killed nearly 15,000 people.
A catastrophic collapse of Mount Unzen’s lava dome unleashed a massive tsunami on Kyūshū, claiming nearly 15,000 lives.
On the night of May 21, 1792, the lava dome atop Mount Unzen collapsed in a massive landslide.
The sudden rock avalanche plunged into the Ariake Sea, generating a powerful tsunami that swept across coastal villages.
Cities such as Shimabara and Fukae were devastated, with timber structures obliterated by towering waves.
This remains one of the deadliest volcanic-induced tsunamis in history, deeply impacting Japan’s disaster awareness.
The tragedy spurred improvements in early warning and volcanic monitoring techniques for future eruptions.
1792
lava dome
Mount Unzen
Shimbara
Japanese
Kyūshū
creating a deadly tsunami
1917day.year
The Great Atlanta fire of 1917 causes $5.5 million in damages, destroying some 300 acres including 2,000 homes, businesses and churches, displacing about 10,000 people but leading to only one fatality (due to heart attack).
The Great Atlanta fire of 1917 devastated 300 acres, destroyed 2,000 buildings, displaced 10,000 residents, and caused $5.5 million in damages.
On May 21, 1917, a catastrophic fire broke out in Atlanta, beginning in a sheet-metal factory and rapidly spreading through the city's wooden structures.
Fueled by strong winds and dry conditions, the blaze consumed approximately 300 acres and destroyed roughly 2,000 homes, businesses, and churches.
Firefighters struggled to contain the flames, and the city's water pressure proved insufficient against the inferno.
Although only one death was officially recorded—a man who suffered a heart attack—the fire left some 10,000 people homeless.
Damage was estimated at $5.5 million, making it one of the most destructive urban fires in American history up to that time.
In the aftermath, Atlanta implemented stricter building codes and expanded its fire department to prevent a similar disaster.
Great Atlanta fire of 1917
1946day.year
Physicist Louis Slotin is fatally irradiated in a criticality incident during an experiment with the demon core at Los Alamos National Laboratory.
Physicist Louis Slotin died on May 21, 1946, after a criticality accident involving the 'demon core' at Los Alamos.
On May 21, 1946, physicist Louis Slotin received a fatal dose of radiation during a criticality experiment with a plutonium core at Los Alamos National Laboratory.
Known as the 'demon core,' the assembly of two hemispheres of plutonium suddenly went supercritical when a screwdriver slipped during a manual test.
Slotin's swift hand motion halted the reaction, but he absorbed a lethal amount of radiation.
He died nine days later, and the incident became a cautionary tale in nuclear safety.
Slotin's accident led to stricter protocols and the development of remote handling techniques for fissile materials.
The 'demon core' was later used in atomic bomb tests and remains a stark reminder of the perils of early nuclear research.
1946
Louis Slotin
criticality incident
demon core
Los Alamos National Laboratory
1976day.year
Twenty-nine people are killed in the Yuba City bus disaster in Martinez, California.
On May 21, 1976, a charter bus plunged into a river near Martinez, California, killing 29 people.
The Yuba City disaster remains one of the deadliest bus accidents in U.S. history.
A bus carrying high school students and their families veered off a mountain road and fell into the Mokelumne River.
Poor visibility and a narrow bridge contributed to the catastrophic crash.
Emergency crews faced swift currents and challenging terrain during rescue operations.
Investigators later cited driver fatigue and inadequate road barriers as factors.
The incident led to stricter safety regulations for school and charter bus operations.
Families and communities mourned the tragic loss of so many young lives.
1976
Yuba City bus disaster
Martinez, California
1996day.year
The ferry MV Bukoba sinks in Tanzanian waters on Lake Victoria, killing nearly 1,000.
The ferry MV Bukoba sinks in Lake Victoria on May 21, 1996, resulting in nearly 1,000 fatalities.
Tragedy struck Lake Victoria on May 21, 1996, when the Tanzanian ferry MV Bukoba capsized and sank, resulting in nearly 1,000 deaths. The vessel, reportedly overcrowded and lacking adequate safety equipment, tilted suddenly in rough waters. Rescue efforts were hampered by poor visibility, insufficient lifeboats, and delayed responses from authorities. Many passengers and crew members were trapped below decks or thrown into choppy waters without life jackets. The disaster prompted demands for stricter maritime regulations and improved enforcement in Tanzania. It remains one of the deadliest maritime accidents on the African Great Lakes.
1996
MV Bukoba
Tanzanian
Lake Victoria
2000day.year
Nineteen people are killed in a plane crash in Wilkes-Barre, Pennsylvania.
A small plane crashes in Wilkes-Barre, Pennsylvania, on May 21, 2000, killing 19 people.
On May 21, 2000, a small charter plane crashed near Wilkes-Barre, Pennsylvania, killing all 19 people on board. The aircraft, en route to a local airport, encountered mechanical issues and poor weather conditions shortly before attempting an emergency landing. Investigators cited pilot error and inadequate maintenance as contributing factors to the tragedy. The crash prompted reviews of regional airline safety standards and maintenance oversight. Families of the victims and local communities mourned the sudden loss. The incident underscored the risks of small aircraft operations in challenging environments.
2000
plane crash
Wilkes-Barre, Pennsylvania
2003day.year
The 6.8 Mw Boumerdès earthquake shakes northern Algeria with a maximum Mercalli intensity of X (Extreme). More than 2,200 people were killed and a moderate tsunami sank boats at the Balearic Islands.
On May 21, 2003, a powerful 6.8 magnitude earthquake struck northern Algeria, killing over 2,200 people and triggering a moderate tsunami in the Balearic Islands.
The Boumerdès earthquake, registering 6.8 Mw, struck the coastal region east of Algiers with devastating force.
It reached a maximum Mercalli intensity of X (Extreme), causing widespread collapse of buildings and infrastructure.
Official reports recorded more than 2,200 fatalities and thousands of injuries across several provinces.
The quake generated a moderate tsunami that sank small vessels in the Balearic Islands.
Rescue efforts involved national emergency services and international aid teams.
The event prompted significant changes in Algeria's seismic building codes.
2003
Boumerdès earthquake
Algeria
Mercalli intensity
Balearic Islands
2012day.year
A bus accident near Himara, Albania kills 13 people and injures 21 others.
On May 21, 2012, a bus crash near Himara, Albania, claimed 13 lives and injured 21 passengers.
The accident occurred when the bus veered off a mountainous road during a routine journey.
Emergency responders faced challenging terrain to reach the wreckage.
Victims included local commuters and tourists traveling along the scenic coastal route.
The crash led to calls for improved road safety measures in Albania.
Investigations examined vehicle maintenance and driver fatigue.
2012
bus accident
Himara, Albania
2024day.year
The Greenfield tornado kills 5 and injures 35 across rural Iowa, United States. Wind speeds in excess of 480 kilometres per hour (300 mph) are estimated from measurements for the third time in history.
A destructive tornado strikes rural Iowa, killing five and injuring thirty-five, with winds exceeding 480 km/h—the third-highest wind speed ever recorded.
On May 21, 2024, a powerful tornado tore through the rural community of Greenfield, Iowa, claiming the lives of five residents and injuring thirty-five others. The tornado's wind speeds were measured at over 480 km/h (300 mph), marking only the third time in history that winds have reached such intensity. Authorities and emergency responders scrambled to assist survivors amid widespread property damage and downed power lines. The scale of devastation prompted state and federal disaster declarations, enabling critical aid and funding for recovery efforts. Meteorologists noted the storm's rarity and destructive power, sparking renewed discussions on severe weather preparedness in the Midwest.
2024
Greenfield tornado
Iowa