When the four-storey building was built behind the beach in the southwestern Gironde region in 1967, it stood 200 metres (220 yards) away from the shoreline.
But its 75 or so flats in the town of Soulac-sur-Mer had to be evacuated in 2014 after the sea crept up to within 20 metres of the structure.
Local authorities scrambled to rid the building of asbestos in the following years, before a huge mechanical digger took a swing at its facade on Friday, as several former residents looked on.
“It’s the memories of four generations” that are being destroyed, said 76-year-old Vincent Duprat, one of the home owners.
The sea “has taken back what is rightfully hers”.
Environment Minister Christophe Bechu said the demolition was a sign of “what the rising waters and coastal erosion have is store for lots of other areas along the French coastline”.
By 2100, 20 percent of the coastline and up to 50,000 homes would be affected, he said.
Erosion is a natural phenomenon that has helped shape our continents over millennia.
But scientists say it is being accelerated by the warming of the planet, exacerbated by rising sea levels brought about by melting ice caps and glaciers, and by the more powerful waves that warmer oceans hold.
The sandy beaches of the Bay of Biscay between France and Spain are expected to recede by 50 metres by 2050, the Observatory of the Nouvelle-Aquitaine Coastline says.
But climate change and rising sea levels could increase this by an extra 20 metres in some areas, the Observatory’s Nicolas Bernon said.
In 2020, after a seven-year legal battle, a court ruled that French authorities should compensate families who had been forced to evacuate the building in Soulac-sur-Mer to the tune of 70 percent of the original value of their homes.