Possible Grenade Explosion Kills 3 Sheriff's Deputies

How many deadly devices are out there? That's the grim question after three sheriff's deputies were killed in what's believed to be a grenade explosion. The tragedy reportedly began when grenades were discovered in an old storage unit at an apartment building in Santa Monica. It's believed the officers, from an elite arson/explosives unit, were rendering the devices safe at a sheriff's facility in Los Angeles when at least one of them went off.