MARTINSBURG - While police have yet to positively identify the source of a Dec. 4 blast that rocked Morrisons Cove, officers said this week that they suspect a powerful-but-legal explosive available at many gun stores.
Martinsburg Police Chief Kerry Hoover said the loud boom - which prompted emergency calls after people across the Cove reported a sudden shaking - might have been caused by exploding rifle targets that sell under the brand names Tannerite and Shockwave.
"I've got some people checking on things," Hoover said Thursday.
Hours after the Dec. 4 explosion, Martinsburg officers identified Tannerite as the likely source of a similar blast last year. Hoover said he's heard similar rumors but couldn't confirm the identities of those responsible.
The proprietary compounds are commonly available at gun and sporting shops, where they are sold as inert chemical compounds until users mix them at home. Tannerite, made of ammonium nitrate and aluminum powder, only becomes explosive when mixed and is detonated by high-powered rifle shots.
While the compound's manufacturer stresses on its website that it is intended to aid target practice, a slew of videos online show users mixing massive quantities and destroying cars, washing machines and outhouses.
"It's becoming a popular thing, too," Hoover said.
Police have ruled out several alternate theories surrounding the apparent explosion: New Enterprise Stone & Lime Co. officials said they didn't carry out any quarry blasts Dec. 4, and evidence hasn't surfaced to indicate an earthquake.
Tannerite and similar products have been identified in other states as the cause of initially unexplained, earth-shaking explosions.
In January, a tremendous blast in western New York drew calls from as far as 30 miles away and across the Pennsylvania border, news reports at the time indicated. Police later pointed to a Tannerite user as the culprit.
Even if Martinsburg police can identify the source and name a suspect, however, it's likely they couldn't file charges.
"It's purchased legally, and there's no limit on quantities," Hoover said.
The explosion would only spur criminal charges if those responsible had endangered people or destroyed property, he said.
On Monday, Roaring Spring Police Chief Milton Fields said his department is backing Martinsburg's in the search. Hoover said he's contacted the federal Bureau of Alcohol, Tobacco, Firearms and Explosives for information on the explosive compounds.
"If I find out that's what it is, I'll put together some sort of a safety message," he said.
Mirror Staff Writer Ryan Brown is at 946-7457.