Arrived to basement floor marked out for leak under slab. Cut tile and broke concrete slab in order to gain access to hot and cold water line below. After location water lines and turned water on to test, found HOT soft copper water line had pinhole/burst on top. Nothing obvious to what have caused pin hole in pipe. Once pinhole was cut at direct location and repaired with press repair coupling the fix was insulated taped and backfilled with play sand to bed and support repair. Continued to back fill hole, lay down 3 MIL vapor barrier plastic and repour concrete as level as possible. Tested everything to ensure proper function.