The Unknown Zone: Unknown Explosion at Narragansett Beach

On July 11, 2015 at Salty Brine State Beach in Narragansett, RI,  60 year old Kathleen Danise was suddenly thrown from her beach chair 5-10 feet into the air as though she was shot out of a cannon according to her sister Laura Demartino.  Mrs. Danise landed on her face and left unconscious for 3 minutes and was left bruised with a concussion and 2 broken ribs.
Immediately preceding this event, witnesses experienced a crash, a massive bang, the sand and jetty rocks shifting and bathers felt what they thought was and earthquake in the water.  The explosion in the sand directly beneath Mrs. Danise left a small creator.  Investigations by the State of RI DEM, the bomb squad and the Coast Guard have come up devoid of answers but have ruled out a bomb or man made explosion and there was officially no seismic activity so an earthquake has also been ruled out.
This is now considered a genuine unknown and Mrs. Danise says that she will not return to her favorite beach until they find out what really happened as she sees the potential danger still exists.
Judy Sellins and Dave Turco, Rhode Islanders themselves will try to unravel the mystery!