MOSCOW, June 10 -- The morning began the way the neighbors have learned to dread. At about 5:30 am on Tuesday, a BMW X3 pulling away from a residential building in Balashikha, just east of Moscow, exploded with enough force to kill the man behind the wheel before help could reach him. Bystanders got to the driver while he was still alive, Russian investigators said. He died at the scene, beside the apartment blocks, in a district that has now heard this sound twice.

Russia's Investigative Committee confirmed the explosion and the death, opened a criminal case, and said its forensic teams were working the scene, while declining to name the victim, ABC News reported. The silence did not hold elsewhere. By Wednesday, Russian military Telegr...