A half dozen mailboxes have been vandalized in Longview... and police want it to stop before somebody gets hurt. Fire marshals say the mailboxes are exploded using a plastic bottle filled with a chemical and aluminum foil. When shaken, it causes a small explosion... Destroying the mailboxes. Investigators say the chemical mixture is sometimes used in science projects... so they believe this may be a case of young people getting into mischief... But they add, that doesn't detract from the serious danger this stunt can pose.