A memory device comprises a stack of conductive layers, and an array of pillars through the stack. Each of the pillars comprises a plurality of series-connected memory cells located in a layout pattern of pillar locations at cross-points between the pillars and the conductive layers. The pillars in the array are arranged in a set of rows of pillars extending in a first direction. First and second source lines are disposed vertically through the pillars of first and second particular rows of pillars. The set of rows of pillars includes a subset of rows of pillars including multiple members disposed between the first source line and the second source line. A source line conductor is disposed beneath and electrically connected to the first source line, the second source line, and the subset of rows of pillars disposed between the first and second source lines.