1939day.year
The U.S. Navy submarine USS Squalus sinks off the coast of New Hampshire during a test dive, causing the death of 24 sailors and two civilian technicians. The remaining 32 sailors and one civilian naval architect are rescued the following day.
The U.S. Navy submarine USS Squalus sank during a test dive off New Hampshire, killing 24 crew members and technicians.
On May 23, 1939, the USS Squalus began a routine test dive off the coast of New Hampshire when a critical failure caused it to flood and sink to the ocean floor. Twenty-four sailors and two civilian technicians perished in the initial disaster. The following day, Navy divers and support ships launched a daring rescue operation using a rescue chamber to save the remaining 32 enlisted men and a civilian naval architect. The successful recovery of survivors marked the first large-scale submarine rescue in U.S. history. The tragedy prompted the Navy to improve safety protocols, inspection procedures, and rescue technology for all future submarine operations.
1939
U.S. Navy
submarine
USS Squalus
New Hampshire
1946day.year
The start of a two-day tornado outbreak across the Central United States that spawned at least 15 significant tornadoes.
A major two-day tornado outbreak began across the Central United States, producing at least 15 significant twisters.
On May 23, 1946, a massive storm system moved into the Central United States, spawning a series of devastating tornadoes across multiple states. Over the next two days, at least 15 significant tornadoes carved destructive paths through rural and urban areas. Entire towns were damaged or destroyed, leaving dozens of people dead and many more injured. The outbreak overwhelmed local emergency services, prompting regional and national relief efforts. Meteorologists studied the event to improve early warning systems, leading to advances in tornado forecasting. The disaster highlighted the vulnerability of communities to severe weather and spurred enhancements in building standards.
1946
two-day tornado outbreak
1960day.year
A tsunami caused by an earthquake in Chile the previous day kills 61 people in Hilo, Hawaii.
A tsunami triggered by the Great Chilean earthquake reaches Hawaii on May 23, 1960, killing 61 people in Hilo.
On May 22, 1960, a massive magnitude 9.5 earthquake struck southern Chile, the most powerful ever recorded.
The quake generated a powerful tsunami that traversed the Pacific Ocean.
Early on May 23, waves up to 35 feet high slammed into the coast of Hilo, Hawaii.
Sixty-one residents and visitors lost their lives, and hundreds of homes and boats were destroyed.
The disaster highlighted the far-reaching impact of megathrust earthquakes and the need for tsunami warning systems.
Hawaii later improved its monitoring and evacuation protocols to mitigate future risks.
1960
tsunami
an earthquake in Chile
Hilo, Hawaii
1971day.year
Seventy-eight people are killed when Aviogenex Flight 130 crashes on approach to Rijeka Airport in present-day Rijeka, Croatia (then the Socialist Federal Republic of Yugoslavia).
Aviogenex Flight 130 crashes on approach to Rijeka Airport, killing 78 people.
Aviogenex Flight 130, operating a domestic route within Yugoslavia, encountered difficulties on approach to Rijeka Airport on May 23, 1971.
The aircraft crashed into a hillside due to navigational errors and poor weather conditions.
All 78 passengers and crew aboard were killed, making it one of the deadliest aviation accidents in the region at the time.
Investigations pointed to a combination of pilot miscalculations and inadequate instrumentation as contributing factors.
The tragedy prompted improvements in approach procedures and air traffic control around Rijeka.
Safety standards for domestic flights in Yugoslavia were subsequently reviewed and strengthened.
1971
Aviogenex Flight 130
Rijeka Airport
Rijeka
Socialist Federal Republic of Yugoslavia
1978day.year
A Tupolev Tu-144 crashes near the Russian town of Yegoryevsk, killing two.
A Soviet Tupolev Tu-144 supersonic airliner crashes near Yegoryevsk, killing two crew members.
During a routine test flight on May 23, 1978, the Tupolev Tu-144 experienced a structural failure.
The aircraft plunged into a forest near Yegoryevsk, southeast of Moscow.
Both pilots aboard were killed in the crash; no civilians on the ground were harmed.
Investigations suggested metal fatigue and design flaws contributed to the mishap.
The accident raised concerns about the safety of the Tu-144 program, the Soviet counterpart to the Concorde.
It delayed further supersonic flights and cast doubt on the aircraft’s commercial viability.
1978
Tupolev Tu-144
crashes
Yegoryevsk
1991day.year
Aeroflot Flight 8556 crashes at Pulkovo Airport, killing 13.
Aeroflot Flight 8556 crashes at Pulkovo Airport, killing 13 people on board.
On May 23, 1991, Aeroflot Flight 8556, a scheduled passenger flight from Riga to Leningrad, crashed on landing.
The aircraft failed to maintain proper glidepath in poor weather conditions at Pulkovo Airport.
Thirteen of the 52 passengers and crew were killed in the accident.
Survivors reported heavy rain and limited visibility during the final approach.
The crash prompted reviews of landing protocols and pilot training within Aeroflot.
Pulkovo Airport upgraded its instrument landing systems to improve safety in adverse weather.
1991
Aeroflot Flight 8556
Pulkovo Airport
2006day.year
Alaskan stratovolcano Mount Cleveland erupts.
Mount Cleveland, an active stratovolcano in the Aleutian Islands, erupts with explosive blasts and ash clouds.
On May 23, 2006, Mount Cleveland, part of the Aleutian volcanic arc, erupted explosively. Pilots reported dense ash plumes reaching tens of thousands of feet, prompting aviation warnings across the North Pacific. The eruption produced lava flows and incandescent tephra cascading down the volcano's flanks. Although its remote location prevented direct human impact, the event highlighted the dangers posed to trans-Pacific flights and the dynamic nature of the Earth's crust. Scientists monitored seismic activity closely, studying ash samples to better understand volcanic processes in the Aleutians.
2006
stratovolcano
Mount Cleveland
2013day.year
A freeway bridge carrying Interstate 5 over the Skagit River collapses in Mount Vernon, Washington.
A span of the Interstate 5 Skagit River bridge collapses after being struck by an oversize load, severing a key north–south corridor.
On May 23, 2013, a concrete span of the Interstate 5 bridge over Washington's Skagit River collapsed when an oversize load hauling machinery struck one of its supports. Motorists watched in alarm as the roadway plunged into the river below, though fortunately no fatalities occurred. Initial rescue operations focused on clearing debris and treating those injured in nearby vehicles. The collapse disrupted a vital trade artery between the U.S. and Canada, forcing lengthy detours and economic impacts for weeks. The incident spurred nationwide reviews of bridge safety, load regulations, and infrastructure maintenance protocols.
2013
Interstate 5
Skagit River
collapses
Mount Vernon, Washington
2015day.year
At least 30 people are killed as a result of floods and tornadoes in Texas, Oklahoma, and northern Mexico.
Deadly floods and tornadoes in Texas, Oklahoma, and northern Mexico kill at least 30 people and devastate communities.
Starting May 23, 2015, extreme weather unleashed powerful tornadoes and flash floods across parts of Texas, Oklahoma, and northern Mexico. Torrential rains caused rivers to swell, inundating homes, roads, and farmland, while twisters carved destructive paths through small towns. Rescue crews scrambled to evacuate stranded residents and recover those trapped in vehicles or buildings. At least 30 fatalities were reported, and hundreds suffered injuries or displacement. The severe storms highlighted the region's vulnerability to sudden weather shifts and prompted discussions on improving emergency preparedness and infrastructure resilience.
2015
floods and tornadoes
2021day.year
A cable car falls from a mountain near Lake Maggiore in northern Italy, killing 14 people.
A cable car plunges near Lake Maggiore in Italy, killing 14 passengers and shocking the tourist hotspot.
On May 23, 2021, a tragic accident struck the Lake Maggiore region of northern Italy when a cable car descending from the mountains above Stresa broke away and crashed to the ground. Fourteen people on board lost their lives in the fall, while a handful of survivors recounted harrowing escapes. Rescue teams navigated steep, rocky terrain to recover victims and provide aid. Investigations were launched into cable car maintenance records and mechanical systems to determine the cause. The disaster sent ripples through the European tourism industry and prompted immediate safety inspections of similar transport systems.
2021
cable car falls
Lake Maggiore