Caused by war or other violent encounters, where have the most people died throughout history within a single day?

These should include deaths at the hands of others, or themselves, using any conventional weapons (swords, bow/arrows/guns, etc).

These could be from beginning of history to today.

For example, during the Rwandan genocide event, there were an estimated 500k-1M deaths, but over a 100-day period.

Edit: This should not be a duplicate of this. Note that the other question doesn't have a time period, but it asks for the certain area in a long time.

Where is the bloodiest area with most violent deaths within a single day?

  • 3
    Possible duplicate of Where is the bloodiest square mile on Earth? May 6, 2019 at 11:24
  • 7
    You have three variables: location, time period, and death toll. To make your question answerable you need to set reasonable constraints/priorities on them. For example, if the total death toll has a priority you'll receive answers like Black Death, WW II and Holocaust although all of these events happened over a large period of time. May 6, 2019 at 11:29
  • Looking for the most violent deaths/day might be one angle, going away from absolute numbers to relative numbers might be another. Absolutes tend skew this towards 20th century time-frame; we are just so much more people now. May 6, 2019 at 12:06
  • 1
    The bloodiest few seconds within the smallest areas would have been during the atomic bombings of Hiroshima and Nabasaki, when thousands who were close enough to ground zero were vaporized in a few seconds. The bloodiest week could have been a week long massacre by Mongols, or the busiest week at Nazi death camps.
    – MAGolding
    May 7, 2019 at 20:57
  • 1
    @Vishwa en.wikipedia.org/wiki/Planck_length May 9, 2019 at 10:02

5 Answers 5


Given that the question asks specifically for conventional weapons (so ruling out Hiroshima and Nagasaki), and is now limited to a 24 hour period in history, you are probably looking at Operation Meetinghouse where 279 B-29 bombers dropped 1,665 tons of bombs on Tokyo on the night of 9–10 March, 1945.

Approximately 100,000 people were killed.

The bombs dropped by the B-29s were mostly E-46 cluster bombs and M-47 incendiary bombs. The E-46 cluster bombs each contained 38 M-69 incendiary bomblets. The M-69 bomblet itself contained napalm.

If you are interested in more details about the weapons employed, you might find Fire warfare : Incendiaries and flame throwers, published in 1946 by the United States. Office of Scientific Research and Development of interest (especially Chapter 1: Incendiary Bombs and Clusters).

The firestorm resulting from the raid caused more than 80,000 casualties. The exact number of dead will never be known, but:

  • 79,466 bodies were recovered and recorded.
  • The Tokyo Director of Health estimated 83,600 people were killed and 40,918 were wounded.
  • The Tokyo Fire Department estimated that 97,000 were killed and 125,000 wounded.
  • The Tokyo Metropolitan Police Department estimated that a total of 124,711 people were killed or wounded in the raid.
  • A report by the United States Strategic Bombing Survey estimated the casualties to have been 87,793 killed and 40,918 injured.

(Figures from Frank, 1999, except as otherwise cited)

The British Pathé news archive has newsreel footage which shows the devastation caused by the raid.

Most historians estimate the total number killed on that night to be between 90,000 and 100,000, but some argue that the actual number may have been much higher.


  • I think this is the best answer so far.
    – ed.hank
    May 8, 2019 at 16:28
  • 1
    @JMS No, it occurred over one night - the 9/10 March 1945. The bombers took off from their bases on 9 March, the first bombing runs commenced at 12:08 am on 10 March (local time). The raid lasted for approximately two hours & forty minutes. Bombers returned to their bases on the morning of 10 March. May 8, 2019 at 16:59
  • 1
    @sempaiscuba, My bad, I also found a second source which said the fire's burned out mid morning March 10th. So all of it occurred on the 10th.
    – user27618
    May 8, 2019 at 17:12

The Rwandan genocide is a fair contender for the top place in terms of casualties per day -- at 5-10k/day.

Another is WW2, which resulted in 70 million to 85 million casualties depending on the estimates (50-56m from the war itself, and another 19-28m from disease and famine), over the course of 2,193 days (Sep 1 1939 to Sep 2 1945) -- 32-39k/day.

A few localized bombing campaigns probably score highest on the list. For instance:

  • The nuke that struck Hiroshima killed 90–146k people -- of which 70-80k killed in a mere few instants, which I'd surmise is the absolute record in history when normalized per day, and hopefully it will remain that way.
  • Operation Meetinghouse (firebombing of Tokyo on Mar 9-10 1945) killed an estimated 100k people in just about 2 hours and 40 minutes -- possibly the highest rate of death when normalized per day (nearly 900k) in the history of conventional warfare.

Several WW1 battles were more localized and did excruciating amounts of casualties -- Passchendaele, Verdun, Somme... The Hundred Days Offensive, which basically ended the war, resulted in 1.8m casualties -- 18k/day.

Also worth noting are a few massacres that stood out in the medieval era and earlier. In no particular order:

  • The Mongols did a few wholesale massacres that captured the imaginations at the time -- Merv and Nishapur in particular. Numbers as high as a million+ are circulating on the web but I'm frankly skeptical because Persia's entire population at the time was around 2.5m. The two main sources on these seem to be Ata-Malik Juvayni and Rashid-al-Din Hamadani, neither of which were born when the events occurred.

  • Timur was equally murderous as he conquered Persia. Here too, the very large numbers are suspicious, albeit less so than those of the Mongols. In The History of Terrorism: From Antiquity to Al Qaeda, Chaliand and Blin (2007) put the number of deaths in Isfahan at 100-200k, while Encyclopaedia iranica and Christensen (1993; The Decline of Iranshahr) both put the number closer to 70k. There also appears to have been a witness at the time who counted more than 28 towers constructed of about 1,500 heads each -- suggestion a bit over 42k.

  • The Romans completely destroyed Carthage. It didn't happen overnight - the process reportedly took 7 days and 6 nights. Between 150-450k Carthagenians may have died. (The 450k number also seems high IMO: the entire Roman Empire had a population of 4-5m by around 100BC)

You'll find a few more good contenders in these two related questions:

Also, if you normalize this further so the rate of death is based on the total population of an area or whatever else expresses the death rate not in absolute but in percentage of applicable population, then by all means Napoleonic battles such as Borodino and Leipzig or some US Civil War battles like Gettysburg deserve a mention here too. As would Nazi concentration camps, which basically industrialized murder.

And if you include diseases, then think Black Death or Columbian Exchange.

  • 1
    Comments are not for extended discussion; this conversation has been moved to chat. May 8, 2019 at 14:56
  • No US Civil War battle is a contender here; the only way you can think that is to confuse casualties (killed, wounded, and captured) with deaths. Gettysburg for example resulted in about 50,000 casualties but only about 8,000 deaths. Over 3 days I might add.
    – C Monsour
    Jun 15, 2019 at 6:53

Strictly following the question's specification

deaths at the hands of others, or themselves, using any conventional weapons (swords, bow/arrows/guns, etc)

On 14 January 1761 there was the Third Battle of Panipat (North of Delhi) when an Afghan army invaded India. The sources that Wikipedia gives add up to a total of minimum 70,000 killed and maximum 85,000.

After the battle, there were "Another 40,000–70,000 non-combatants massacred". Some of these deaths were on the same day as the battle but others were the next day (I don't think anyone can say how many on each day).


If you want within a single day and within a very confined area like a square kilometer, then the final suppression of the Nika riots on or about 18 January 532 AD is a good contender. (See here and here.) With 30,000-35,000 rioters in the Hippodrome in Constantinople, the imperial troops blocked the exits and slaughtered everyone.

I realize there are some battles with higher one-day death tolls, but most battles take place over considerably larger areas.

Also, since the Hippodrome was only about 10 hectares (1/10 of a square kilometer), you could make the space requirement quite small and still count the full death toll.


He is asking in a SINGLE day over a few square miles?

I have no idea, but I am going to guess it was the battle of Cannae for battle deaths (estimated at about 80,000).


It was fought on a relatively small area, and a lot of romans died.

And Hiroshima, for just the most number of deaths in a small area in a day. Estimated at 90,000. (and the blast radius of the first atom bomb was very small just a couple of miles at most)


I would have included the Tsunami of 2004 https://en.wikipedia.org/wiki/2004_Indian_Ocean_earthquake_and_tsunami .. 200k+ people died, but over a VERY large area, in a single day.

  • 1
    I would think the Battle of Aquae Sextiae would have had even more casualties than Cannae. In addition to the the Teutone & Ambrone armies that were wiped out, the camp followers and women/children committed mass suicide. Roman records say 200k were killed and 100k captured, of course these numbers are most likely exaggerated.
    – ed.hank
    May 8, 2019 at 16:27

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.