Images show a huge chunk of rock weighing more than 1,000 tonnes, come crashing down onto a beach from 150 foot cliffs in Dorset.
A small 'puff of dust' can be seen coming from the middle of the sandstone cliff, at West Bay, second before the massive rockfall at 10.53am on January 18.
The fall immediately weakened the neighbouring rock buttress which then went the same way and luckily the beach was empty due to the cold and cloudy conditions on the day.
Footage was from the Environment Agency's fixed camera on the pier at West Bay.
A spokesman for Dorset Council's Jurassic Coast Team said: "You can see the way these cliff falls work. They fall vertically, they just collapse from the sheer weight probably caused by groundwater and the weakening of the cliff from underneath.
"But it's not over yet because the nextdoor buttress has been weakened by the fall and there it goes. My goodness, it is enormous. As the dust begins to clear the sun comes out and shines a light on the enormous pile of debris left.
"I think we should all be very grateful there was nobody anywhere near this when it took place."
Witness Chris Emmerson described the sound of the rockfall like a "rumble of thunder".
Mr Emmerson, 39, from Crewkerne, said: "It was quite incredible. We were stood on the cobb wall and heard a rumble like thunder in the distance. I turned around and saw the first of two cliff falls and a big cloud of dust.
"By the time I got my phone out to take pictures the second fall happened in the same place. It was like an old chimney stack coming down.
"I called the coastguard and they asked me if we had seen anyone on the beach at the time."
Fresh warning signs have been put up and the coast path has been temporarily closed while council engineers assess the site.
West Bay, in the heart of Britain's UNESCO World Heritage Jurassic Coast, was the real-life setting for the ITV crime drama Broadchuch and is a tourist hotspot.
The landslip is the latest in a series of rockfalls which have taken place on this crumbling stretch of 180 million year old cliffs in the past few years.
