The devastating 1607 flood disaster which killed 2,000 people along the Bristol Channel coastline, including many in the Burnham area, is the focus of a major BBC2 TV documentary this week.
The BBC's Timewatch programme, The Killer Wave of 1607, to be aired on Friday, examines whether the disaster of January 1607 was caused by a combination of freak high tides and hurricane-force winds or a rare tsunami similar to the one that devastated Asia last December.
Experts believe the flood was caused by a 10 metre high wave moving up the Bristol Channel at speeds of up to 100mph, giving no warning to people caught in its path.
According to historical accounts, sea water rushed inland and inundated some 200 square miles of land across Somerset and South Wales. The sea water at Burnham went inland as far as Glastonbury, making it the largest and most destructive flood in British history.
Some 30 villages in the Burnham area were inundated, with historical records stating that 28 people were killed at Huntspill and a further 26 at Brean.
Using historical records from the day, the BBC examines scientific evidence gathered in recent years and also recreates the fateful day through the eyes of a milk maid at Berrow and a Brean landholder, John Stoles, whose family perished.
In the programme, Professor Simon Haslett of Bath Spa University College says: "You can't really imagine what it must have been like, other than the human tragedy of it. Quite catastrophic and how people dealt with it is amazing."
He adds: "A lot of commentators on the 1607 flood have put it down to a storm coming in and as a child you accept what you are being told by scientists and hostoricals and you don't really question it."
But he questions whether a storm was really to blame. The programme looks back at recent large storms, such as the one on December 13, 1981 - the biggest in living memory - when low pressure in the Atlantic forced sea water up the Bristol Channel, and combined with high tides and snow melt to bring crashing waves over the sea wall at Burnham and Weston. It was a heavy storm, but did not match up to the force of the 1607 flood.
By looking at boulders, the shape of cliffs and silt along the Bristol Channel coast, Simon Haslett and Ted Bryant, an Australian geologist, believe they have gathered enough evidence to show the 1607 may have been caused by a tsunami.
Dr Roger Musson, Head of Seismic Hazzards at the British Geological Survey, adds that the sea bed off the south west tip of Ireland is the location of an ancient and large fault line that could have caused a 1607 tsunami. "This is exactly the sort of place where you could get an anonymously large earthquake happening," he says.
Indeed, an earthquake occurred there on February 8, 1980 when trembles measuring 4.5 on the Richter Scale were recorded. "The idea of putting a large hypothetical hisorical earthquake in this spot is not fanciful," concludes Dr Musson.
And Ted Bryant's studies of the silt and historical accounts also seems to back the idea that this was a tsunami. He says: "The size, speed and strange sparkling of the waves all fitted the characteristics of a tsunami."
Tsunamis are certainly rare in the UK, but not completely unheard of. Some 7,000 years ago, the entire east coast of Scotland was battered by a tsunami after a landslide in Norway created waves 70ft high.
And in 1755 an earthquake near Lisbon sent a series of tsunamis into the Atlantic, leading to the south western tip of Cornwall being hit by a 3 metre high wave.
The programme concludes that if the Somerset event of 1607 were repeated now, people along the Somerset coast would be likely to receive plenty of warning if it were a preditctable storm. However, it warns that little or no warning would be given if it were a sudden tsunami.