On the night of 11 March 1864, assisted by a strong south-western gale, the newly built dam, known as the Dale Dyke Dam in
Bradfield Dale near
Low Bradfield on the
River Loxley, collapsed while it was being filled for the first time. An estimated 3 million cubic metres (700 million imperial gallons) of water swept down the Loxley Valley, through
Loxley Village and on to
Malin Bridge and
Hillsborough, where the River Loxley joins the
River Don. The flood continued south down the Don into Sheffield centre, around the eastward bend of the Don at
Lady's Bridge, then to
Attercliffe, past the sites of what later became
Don Valley Stadium,
Sheffield Arena and
Meadowhall Centre, and on to
Rotherham. A wall of water moved swiftly down the valley, destroying everything in its course. The centre of the town, situated on the hill to the south, escaped damage, but the densely populated district of the
Wicker, around the
new railway viaduct (constructed by the
Manchester, Sheffield and Lincolnshire Railway), was completely destroyed. John Leather and resident engineer John Gunson were working closely together during the construction of the dam. Leather designed the dam and looked over its construction whereas Gunson directed and supervised the construction of the dam. ==Aftermath==