Stephen Caswell, 37, a geology lecturer at Plymouth University, his wife Pamela, 40, an education adviser, and her son by a former marriage, Simon Painter, 16, were roped together and climbing down from the summit of Europe's highest mountain when a snow bridge collapsed under them on Sunday.
Mrs Caswell and Simon lost their footing and fell. After a desperate struggle to hold their weight, Dr Caswell also lost his grip. He landed head-first at the bottom of a crevasse, breaking a leg and suffering serious head injuries. Mrs Caswell apparently landed on top of him 100 feet (30 metres) down. She was bruised and scratched and her son suffered a twisted leg.
Shortly after the accident bad weather closed the trail they had been climbing and they were stranded. Dr Caswell died after five or six hours.
Mrs Caswell and her son survived because they were equipped with food and warm clothes and were able to boil water from melted snow on a gas stove as temperatures dropped to -5C. They used the dead man's clothes for extra warmth. 'They were very, very lucky. It's not normal to stay two nights in a crevasse and survive,' said Rudolfo Bornei, an alpine guide.
By the time a passing group of mountaineers noticed the flashing torches being shone by the mother and son to attract attention and had called a helicopter rescue team they had been on the mountainside for 40 hours.
Mrs Caswell and Simon were taken to hospital in Chamonix, suffering from hypothermia, frostbite and shock. Dr Caswell's body was flown to Courmayeur in Italy.
The rescue services said that high temperatures in the Mont Blanc region had made conditions treacherous because normally firm pathways had become slippery as snow and ice began to melt.
The Caswells, recently married, lived in Hartley, a Plymouth suburb. Jackie Curtis, who was looking after their house, said: 'They are a very active family and were always going out mountain-biking and walking.'
Last week eight climbers were killed in an avalanche, also on the Italian side of the Mont Blanc massif.Reuse content