Scientists have concluded that combustion of built-up hydrogen gas in beach sand from an abandoned copper cable caused the explosion at the Salty Brine beach in Rhode Island on July 11.
In a statement, the Rhode Island Department of Environmental Management said oceanographer Dr. Arthur Spivack made the conclusion.
The U.S. Coast Guard previously used the cable, according to RIDEM.
Since the explosion, the DEM has removed the cable and made sure the beach is safe, according to the statement.
The explosion injured a woman.