PLUM ISLAND, Mass. -- A massive dune built to protect families living on the edge on Plum Island is running into trouble, and, this time, it's not the Atlantic Ocean.

"Our biggest problem this weekend was people," said Ron Barrett, of the Plum Island Taxpayers Association.

Barrett and his team spent the entire winter constructing an emergency sand dune. He said he watched careless beachgoers ransack it in two days, pulling out newly planted sea grass, climbing up the dunes and damaging the handmade sandbags that a special team took months to fill and stack.

The dune was built to prevent flooding and protect homes. Project managers said they expected the ocean to knock down their efforts -- not fellow beach lovers.

The message for now is to keep off the dunes -- especially the sandbags -- to keep the delicate infrastructure that keeps everything above it standing.