Cinder Pits Inundation, 1838

After two days of incessant rain followed by snow, the sky over Waun Afon and the Coity darkened about midday on 28 November 1838 and discharged. The water inundated the works, nearly filled the valley, raised the river by many feet and burst over the embankment protecting the mouth of the Old Level at Blaenavon. Fifteen people in the workings were drowned, five of them children and two of them girls. It was Blaenavon's worst industrial accident.

Cause

A sudden and enormous discharge of water from the hills after two days of rain and snow, which inundated the works, raised the river by many feet and burst over the embankment protecting the mouth of the Old Level, flooding the workings behind it.

Contributing factors

The mouth of the Old Level stood below the river and depended on an embankment to keep the water out. Once that was overtopped there was nothing between the river in spate and the men, women and children underground.

What happened

It had rained for two days and then snowed. About midday on 28 November the sky darkened suddenly with dense cloud gathered over Waun Afon and along the Coity in the district of Varteg, and discharged all at once. The water came down, inundated the works and almost filled the valley, raising the river many feet in moments and bursting over the embankment that protected the mouth of the Old Level leading to the Blaenavon Company's deep coal and iron workings. Residents of forty years' standing described the flood, from its foam and volume, as looking like a rolling pack of wool. On the far side of the hill at Varteg it came so suddenly that three young people were drowned in a house beside the river. Fifteen of those in the workings did not get out.

Rescue & recovery

Recovery took a fortnight. By 13 December all the bodies except one — that of a little boy — had been recovered, five of them found on that day alone. All but one had been buried by 29 December.

Investigation & inquiry

No inquest report or official inquiry into the inundation has been found in the sources consulted.

Legal & regulatory aftermath

Nothing recorded in the sources consulted.

Changes to practice & legislation

Nothing recorded in the sources consulted.

Memorials & commemoration

No memorial specific to the inundation has been identified. The Blaenavon parish records contain the names of many local men, women and children killed in industrial accidents.

Recorded claims

Individual factual claims, each attached to the source(s) that support it below. Where sources disagree, both are kept.

• Fifteen people were drowned in the workings; the Welsh Coal Mines list names all fifteen and the Blaenavon World Heritage Site's history records five of them as children. ^1,2
• Two days of incessant rain and snow were followed about midday by a sudden discharge from cloud over Waun Afon and the Coity, which inundated the works and burst over the embankment protecting the mouth of the Old Level. ²
• By 13 December all the bodies except that of a little boy had been recovered, five of them found on that day; all but one had been buried by 29 December. ²

Photographs & further reading

This page doesn't try to reproduce everything — these are the best original sources found for this disaster.

Sources

1. (secondary) Big Pit: A Brief History — Blaenavon World Heritage Site
2. (secondary) Welsh mining fatalities, 1838: Cinder Pits, Blaenavon, inundation of water, 15 killed — Welsh Coal Mines

Record created: 4 September 2026 · Last researched: 4 September 2026