RHODE ISLAND:  Rhode Island's top environmental official says scientists trying to figure out the cause of a mysterious beach blast that sent a woman flying into a jetty are now pursuing a specific cause.

Department of Environmental Management Director Janet Coit says they have "narrowed it down," but she isn't disclosing their theory until testing finishes.

A Waterbury, Connecticut, woman was thrown into a jetty at Narragansett's Salty Brine beach after a loud boom July 11.

Investigators didn't find evidence of an explosive device.

Scientists began looking at whether the soil is suitable for chemicals that can cause explosions, such as hydrogen and methane.

Coit says she initially thought the mystery might never be solved.

She says it now looks like she will either know what happened or have a very good theory.