TACOMA, Wash. -

Prosecutors in Washington state say a couple collected used ammunition from Joint Base Lewis-McChord and melted it down at their home to sell as scrap metal.

The operation went undiscovered for a year until a bullet exploded in January and blew a hole in the floor just above where two children were sleeping.

The News Tribune reports 27-year-old Cody Hyman and 32-year-old Juliette Parker of Tacoma have been charged with possession of an explosive device, assault and reckless endangerment.

The couple who now live in Texas are set to be arraigned June 23 in Tacoma.