The premature explosion rained shrapnel over a closed portion of the highway, hitting a California Highway Patrol vehicle.

A Marine Corps investigation could not conclusively say why the artillery shell's fuze malfunctioned but said no misconduct involved.

The electronic device that was used is manufactured to a standard of “one defect in a million,” and no human error was found, Marine investigators said of the Camp Pendleton incident.

In a 40-year career as an international correspondent for The New York Times, Mr. Burns had a talent for capturing the sweep of history in intricate detail.