A famous rock structure in the form of an arch in Malta collapsed into the sea on Wednesday, in what Maltese prime minister Joseph Muscat described as a “heartbreaking event”.

Geologists had long warned that the structure, on the northwestern coast of the small island of Gozo, was eroding fast. Authorities had already banned visitors from walking on top of it.

The structure, known as the Azure Window because it arched over blue seas, collapsed as Malta was hit by rough seas and stormy weather.

Gozo resident Roger Chessell said he had gone to the coastline in the morning to take pictures.

After Before Photographs: @Jonathan_Atha/Twitter

“There was a big raging sea beneath the Azure Window,” he told the Times of Malta newspaper.

“Suddenly, the arch collapsed into the sea with a loud whoomph, throwing up a huge spray.”

Mr Muscat said in a tweet that the Mediterranean landmark had always faced destruction because of natural corrosion.

“That sad day has arrived,” he wrote.

Reuters