  We investigate dynamics of magnetic thin-shells in three dimensional anti de
Sitter background. Because of the magnetic field, an oscillatory solution is
possible. This oscillating shell can tunnel to a collapsing shell or a bouncing
shell, where both of tunnelings induce an event horizon and a singularity. In
the entire path integral, via the oscillating solution, there is a non-zero
probability to maintain a trivial causal structure without a singularity.
Therefore, due to the path integral, the entire wave function can conserve
information. Since an oscillating shell can tunnel after a number of
oscillations, in the end, it will allow an infinite number of different
branchings to classical histories. This system can be a good model of the
effective loss of information, where information is conserved by a solution
that is originated from gauge fields.
