The first child, A, was unable to handle the pressure of living up to L and took his own life, and the second child, Beyond Birthday, was brilliant and deviant.

Mello (Death Note: Another Note, p. 105)

A was the original potential successor of L and a former resident of Wammy's House.

A was a member of the first generation of potential successors along with B, and he was the first child in line to be L's successor. However, the first generation were "prototypes" and "expected to fail", according to Mello. A committed suicide when the pressure of having to succeed L became too much to handle.