Bloodiest Single Day in History?

I’m curious about this one. It seems that fatality (not casualty) reports for historical events vary wildly. Are there some semi-definitive numbers for the bloodiest day in history? The wikipedia page for death tolls seems highly suspect. For example, it lists the Battle of Borodino at 18,500, but the wiki entry for Borodino says 66,000. Also, we’re talking about a single day, so stuff like the Battle of Somme (400,000), or Nanking Massacre (300,000) doesn’t count, as they spanned weeks. And for sake of argument, let’s exclude “history” before 1700, as I’m skeptical of the accounting accuracy from those periods (e.g. “600 men/minute” for during the day at Cannae in 216 BC). For stuff like Hiroshima, I’m interested in how many died in the first day, not all the rest in the following weeks or years.

Some likely candidates:

Hiroshima - 90,000?
Battle of Borodino - 66,000?

As a side note, looking around it sure seems like Russia has absorbed more than its fair share of deaths over the centuries.

My first thought was the Battle of Antetiem at 23,000 killed.

The firebombing of Tokyo killed about 100,000 people – almost all civilians.

I think we’ve done this before, but I can’t find the thread.

In any case, especially if “bloodiest” is defined to include wounded, it’s hard to beat the first day of the Battle of the Somme (July 1, 1916).

Dresden was close to Tokyo, as far as the number killed.

If we’re just talking about the bloodiest day – not bloodiest battle – I’d imagine that the Tangshan Earthquake, with at least a quarter of a million killed, has got to be near the top, along with the 2004 tsunami in the Indian Ocean.

The Romans lost 60,000 men in one day at the Battle of Cannae

The 1970 Bangladesh Cyclone. One day - 500 000 (plus 100 000 missing).

Wikipedia has a List of deadliest natural disasters (as you might expect). Those with overv half a million on a single day are:

1970 Bhola cyclone – November 13, 1970
Eastern Mediterranean Earthquake – July 5th 1201
1938 Yellow River flood – June 9th, 1938
Shaanxi Earthquake – January 23, 1556

(I got the date of the 1201 earthquake from the 1201 page – although there is no article on that specific earthquake, it may be the worst one-day natural disaster.)

23,000 casualties, but the actual number of dead (cf Shelby Foote) was around 5000. It was the bloodiest day of the war (and the bloodiest day in US history), but most battles list casualties, which include wounded.

Not up among the other natural disasters (maybe 2500 kills), but the worst fire in US history took place on October 8, 1871, and is almost completely forgotten because another, less deadly fire occurred on the very same day and hour. The lesser fire is known to all Americans as one of the country’s great disasters, but the Great Peshtigo Fire deserves to be better know.

Kurt Vonnegut, in his new book, puts the number of dead at Dresden at 135,000. However, I found several other of his historical “facts” to be dubious. And as with many such disasters, there was never any good way to do an accurate census or count of the dead.

There is no question that nature is far bloodier over shorter times than we humans have had the audacity to be.

Dude, try reading all of the OP, not just the title.

This figure actually stems from the notoious Nazi apologist David Irving, and he’s since retracted it in a vain attempt to retain what little credibility he had as a historian.

Wiki says:

As a point of reference, according to this cite, 155,000 people die every day of all causes. He goes on to mention that the 2004 tsunami nearly doubled the death rate for that day.

It would be interesting to recalculate the numbers for the events in previous posts to figure them as percentages of the world population at the time, and also of the daily average death rate at the time.


25,000 vs 100,000 according to Wiki.

Wikipedia says about 36,000, as an upper limit, for the Mount Pelée eruption, with similar numbers for Krakatoa. (Pelée’s dead were pretty certainly from one day, and one town, though.)

Also says that the 1931 Yellow River Flood killed between 900,000 and 2 million, but it doesn’t say over how long.

And the 25,000 were not all on a single day.

My first guess was the December 2004 earthquake and the resulting tsunami in the Indian Ocean. It killed about 200,000 people, but again I don’t know over which period. It could have been several days since the tsunami wave needed some time to travel across the sea.


According to that same site, and the site it links to, an earthquake in China’s Shaanxi province that caused the death of 830,000 people on January 23, 1556. I think this casualties ought to have occured on that very day.

And at their own hand.