Oxford OPP are investigating a mailbox explosion in Norwich. Wednesday night, a homeowner heard a loud bang, followed by three more bangs, and then a vehicle driving away. It happened between 10:15 and 10:30 p.m. The next morning, they found their mailbox severely damaged. Inside with an exploded pop bottle with some aluminium foil. OPP are warning that although this may seem like a harmless prank, playing with explosive material can have serious consequences.