A section of the sea wall at Kingsdown collapsed due to stormy weather as passers-by walked along the promenade.
The concrete was destroyed on Saturday afternoon, on a popular part of the promenade between the Old Lifeboat House and the Zetland Arms.
It was not the first time part of the promenade had collapsed, and residents believe something needs to be done about the sea defences at Kingsdown.
The owner of the Lifeboat House, Helen Williams, was alerted by passers-by.
She said: “A group of people were walking along the promenade. They were standing on it just as it started to collapse.”
The walkers were unhurt and knocked on Mrs Williams’ door to ask her for help. She then contacted the district council and secured it with rope herself before officials arrived to tape up the damage.
The tide was extremely high on Saturday, reaching 6.9 metres, which is one of the highest recorded for Kingsdown.
Daniel Couzens, of North Road, a campaigner for better sea defences, said: “It’s like a domino effect, once one wall goes the others follow. It’s a real worry what’s going to happen next with this weather and high tides continuing.
“It’s a real danger. This collapse is in quite a dangerous position on the promenade, which is a popular place for people to walk.”
Mr Couzens and his partner Karen Brewer are members of the Kingsdown Conservation Group and have been campaigning for long-term sea defences for a number of years.
Last year another part of the promenade collapsed, which reportedly took six months for the council to fix.
Mr Couzens added: “We have been pressing the council to take the sea defence issue in Kingsdown more seriously. They patch up the collapse but then haven’t dealt with the bigger problem.”
The council has only implemented short-term emergency work, which can be costly.
He added: “Dover District Council needs to take control and push for some money to make it safer. Kingsdown is a historic village and it needs protecting.”
Work to rebuild and strengthen the damaged sea wall to the north of the Old Lifeboat House was completed last year.
The district council has been working with the East Kent Engineering Partnership on a proposal to the Environment Agency so that the 14 existing groynes can be replaced by 16 realigned ones, followed by beach replenishment.
Mr Couzens added: “It’s a strong proposal, costing around £3 million, which is well under the £8 million previously estimated by another contractor.”
Kingsdown Conservation Group and the residents who live near the promenade are still to hear if the Environment Agency will accept this proposal.
Mr Couzens added: “This is a band aid solution for something that needs proper attention.”