A “one in a million” malfunction during a live fire demonstration over Camp Pendleton last October led to a misfire that rained shrapnel on Interstate 5, striking two California Highway Patrol vehicles, a US Marine Corps investigation found.

A “one in a million” malfunction during a live fire demonstration over Camp Pendleton last October led to a misfire that rained shrapnel on Interstate 5, striking two California Highway Patrol vehicles, a US Marine Corps investigation found.