Drone photographs have revealed the extent of the latest erosion damage in Hemsby.
Coastal residents said they were in "complete shock" after high tide and winds caused part of a clifftop road to collapse and brought down power lines.
A section of cliff and dune at Hemsby, Norfolk, partially collapsed and was washed away on Friday.
Some residents were left without power and water and had to leave their vehicles after roads were cordoned off.
Simon Measures, chair of Save Hemsby Coastline, said: "It was an utter shock."
He said: "Within minutes people were saying that there was a crack in there [the road] and then instantly it's collapsed, it's gone - the road's disappeared."
Mr Measures said had been no yellow storm warning and that many residents had not thought this could happen so quickly.
The crew of the independent Hemsby Lifeboat helped residents while Norfolk Police closed off some roads.
Hemsby Lifeboat posted on Facebook to say a 200m (220yd) stretch of road had fallen on to the beach.
It warned people to stay away, saying: "It's just too dangerous".
It said the erosion was due to the spring tide that had led to fallen power lines, and left cars stranded on The Marrams, which runs parallel to the cliff.
Local resident Jordan said he was "devastated".
"Now it's all gone and outside my place, which is the end of the road, has fallen into the sea," he said.
Pascal Rose, who was forced to leave her Mini car, said: "We've got so many vulnerable people here that are stuck.
"Now we've got no road; we've got nothing. We are completely cut off."
Michael Szawlytko, who has lived in Hemsby for 10 years, said: "I walked up here last night, thought this road would be all right but it disappeared overnight."
He is among residents who have had to cut through their gardens to gain access to their homes.