Michael Jones, 31, from Burton in Lonsdale, North Yorkshire, was hit by a surge of floodwater 300 yards underground. He had entered caves in the Yorkshire Dales on Sunday with two companions.
Terry Aitkin, from Kendal, Cumbria, struggled to the surface to raise the alarm. Gillian Ridgeway, also from Burton in Lonsdale, who had been sheltering on a ledge 400 yards into the pothole, was taken to Lancaster hospital suffering from hypothermia on Sunday. Mr Jones was certified dead at the scene yesterday.
The Meteorological Office issued a severe weather warning yesterday as gales and wintry showers, from a record low pressure system, hit the country. In Scotland, gusts of more than 100mph were recorded off the north coast, hampering attempts to salvage oil from the wreck of the tanker Braer on the Shetland Islands.
Snow fell in the North, the Midlands and Wales and there was flooding in parts of the Midlands, the South and the West. In Northern Ireland the first heavy snowfalls of winter caused a spate of road accidents. No serious injuries were reported.
Heavy snow and blizzards, in some places the worst for a decade, forced airports and schools to close in Scotland. More than 18 inches of snow fell around the Lochaber area and nine inches in Sutherland. Three inches fell in three hours around Perth.
Part of the main route into the Highlands, the A9, was closed as conditions, especially severe in Caithness, worsened. Snow drifts blocked the A94 south of Stonehaven.
The Forth road bridge was shut and parts of the M8, the main route between Glasgow and Edinburgh, had to be closed after a power line fell near the road. Downed cables around Falkirk and Glenrothes left hundreds of homes without electricity. The highest tides for 40 years hit Stromness in mainland Orkney.
Low pressure of 916 millibars was recorded near the Faroe Islands, equalling the British record. Pressures normally lie between 970 and 1020 millibars.
In London, where gusts reached 50mph, the Thames flood barrier was raised as a precaution. A National Rivers Authority spokesman said: 'There is a large build-up of water. We have not seen sights like it for years.'
In South Wales, British Rail suspended train services in some of the valleys because of flooded lines. Driving conditions in Mid-Wales were hazardous with up to two inches of snow on the A44 between Aberystwyth and Llangurig. Police warned motorists to observe speed restrictions on the Severn Bridge as gales swept the Bristol Channel.
Sandbags were used to bolster sea defences on many west-facing coastal areas.
Forecasters say the bad weather is likely to continue for several days with snow falling as far south as the Cotswolds and the Chilterns.
Local authorities have been told to expect structural damage.