The man was pronounced dead at Cape Cod hospital in Hyannis. The beach has since closed, according to the Associated Press.
The two legislators thanked the Wellfleet Fire and Police departments, the town's beach staff and bystanders "whose preparation and quick action provided help as soon as possible".
Mr Booth said the attack victim and his friend were boogie-boarding when the attack happened.
Harbourmaster Nathan Sears said: "We are witnessing sharks feeding aggressively in shockingly shallow water on an nearly daily basis over this past August". He realised what was happening when the friend came ashore dragging his injured friend.
Beach-goers carry a shark attack victim down Newcomb Hollow Beach. Booth said. "It was like right out of that movie Jaws".
"The inshore waters off Wellfleet are a feeding ground for Great White Sharks", the sign reads. The swimmer, William Lytton of Scarsdale, N.Y., was wading about 30 yards off of the shoreline when he was bitten - becoming the first person to be attacked by a shark in MA waters since 2012, according to WBUR.
The attack is being investigated by State Police and the Cape and Islands District Attorney's office.
Leslie Reynolds, chief ranger at the Cape Cod National Seashore, confirmed the incident that happened about 300 yards south of Newcomb Hollow Beach.
Hayley Williamson, a Cape Cod resident and former lifeguard who was on the beach at the time, was in disbelief after the man was rushed into an ambulance.
"We've been surfing all morning right here and they were just further down", she said of the two boogie boarders.
This is the second shark attack to take place in Cape Cod this summer. "Right spot, wrong time, I guess".
Great white shark sightings in Cape Cod have soared this year, with experts blaming increased seal levels close to the region's beaches.
He sustained severe injuries to his legs and is still recovering in hospital. He freed himself by punching the shark in the gills, he told the Boston Globe.