Investigators have discovered the cause of an explosion at a Rhode Island beach.

Share story

PROVIDENCE, R.I. — A mysterious blast on a Rhode Island beach likely was caused by the combustion of hydrogen gas that had built up because of a corroded copper cable under the sand, investigators announced Friday.

Officials have spent nearly two weeks trying to figure out what happened on July 11 at Salty Brine Beach in Narragansett, when witnesses heard a large boom and a woman from Connecticut was sent flying through the air into a jetty. Police almost immediately ruled out an explosive device or intentional act, but scientists were stumped about what could have caused the blast.

Janet Coit, director of the state Department of Environmental Management, said Friday that scientists had pinpointed it to hydrogen released by the corrosion of an abandoned copper cable that previously was used by the U.S. Coast Guard.