Draw from the live wall for normal draws, and dead wall for replacements.
After the dice break, the wall has two distinct ends. The live wall is the main draw pile: after the initial deal, ordinary turns draw from the live wall in order.
The dead wall is a reserved section of 14 tiles, or 7 stacks. After the break is made, those 7 stacks are taken from the back side of the break, opposite the side where the dealer starts taking tiles.
The dead wall is used for replacement tiles. When a player declares a Kong, they also draw the replacement tile from the dead wall before discarding.
If the live wall runs out before anyone wins, the hand ends in a draw. The dead wall does not become a normal draw pile.