Swept away: $500,000 sand dune built to protect US homes disappears in days | Massachusetts

A sand dune that cost homeowners on a Massachusetts beach more than half a million dollars to construct has washed away after just three days.An affluent group of beachfront property owners in Salisbury, Massachusetts – a coastal town 35 miles north of Boston – are mourning the loss of their investment after a safety measure they took to protect their homes failed.The dune, made of 15,000 tons of sand, was meant to keep dangerous tides from encroaching on to the shore and damaging beach houses. The dune had just been completed in February but was gone within 72 hours.Salisbury Beach…