August 31, 1854

1854 Broad Street cholera outbreak

The Broad Street cholera outbreak begins in Soho

Four fatal cases on the Thursday became seventy-nine more across the Friday and Saturday.

31 August 1854, around Broad Street

A sudden concentration of fatal cholera attacks began around Broad Street in Soho on 31 August 1854. John Snow later treated that Thursday as the outbreak's starting date.

In his initial series of 83 deaths, covering 31 August to 2 September, four fell on the Thursday and the other 79 across the next two days. About 500 died in the intense local period to 9 September, and the UCLA John Snow project puts the final neighbourhood toll at 616.

What Snow did not do that day

He did not map the district, address the parish board, or have the pump disabled on 31 August. Those steps came as the deaths multiplied.

His inquiries found that 68 of 75 early deaths with known water histories involved Broad Street pump users. The nearby workhouse held 535 inmates and recorded only five cholera deaths; its residents drew from their own well.

The handle came off after the peak

Snow addressed the Board of Guardians of St James's Parish on 7 September, and the pump handle was removed on 8 September — by which point fatal attacks had already been falling for days.

A later inquiry found defective brickwork letting sewage from an adjacent cesspool percolate toward the well, 2 feet 8 inches away. Household inquiries by the curate Henry Whitehead pointed to Frances Lewis, a five-month-old at 40 Broad Street, as a possible index case.

Whether she actually had cholera cannot now be proved; her physician recorded acute diarrhoea rather than cholera.

Sources

Researched 23 Aug 2026 6 sources 2 audit passes

How this was checked

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What the sources leave uncertain

Snow designated August 31 as the beginning based on his fatal-case series. Later reconstruction proposed that illness in the possible infant index case began several days earlier.
Whether Frances Lewis actually had cholera cannot now be proved; her physician recorded acute diarrhea rather than cholera.
The removal of the handle was prudent, but available case curves cannot establish that it stopped the already-declining outbreak.