Thousands of tons of rock fell into the sea at Beachy Head last night.
The Dover Coastguard and the Eastbourne Lifeboat received reports that a huge rockfall had happened at Falling Sands just west of the historic landmark.
They believe the rock fall of 250ft into the sea may have been as large as the drop in January at Beachy Head which left the Belle Tout lighthouse at Beachy Head just 12ft from the cliff edge.
Work is currently underway to move the 165-year-old lighthouse, which is now a family home, inland.
A crew from Eastbourne Lifeboat noticed the falling cliff as they returned to base from a rescue at around 6.30pm last night.
Coxswain Dave Corke said it marked the latest in a series of falls right along the English coastline.
He said: "What is responsible is a combination of the very heavy rain that occurred during the autumn combined with frost during the winter.
"It is very precarious out there today. I wouldn't recommend anyone walking along there at all because, as it proved last night, it can fall at any time."
The last major fall along the stretch of coastline happened in April when the 200ft Devil's Chimney collapsed into the sea following incessant rainfall.
It prompted white witch Kevin Carlyon, from Hastings, to perform a ceremony to rid the chalk landmark of what he said was an ancient curse.
But today lifeboatmen were worried that with the summer season fast approaching walkers could find themselves at risk.
Eddie Buckland, who works for the Eastbourne Lifeboat Station, said: "People have got to be especially careful now."
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article