  Using an asymptotically exact real space renormalization procedure, we find
that the Heisenberg antiferromagnetic spin-1 chain undergoes an impurity driven
second order phase transition from the Haldane phase to the random singlet
phase, as the bond distribution is broadened. In the Haldane phase and near the
critical point, there is a Griffiths region in which the gap is filled and the
susceptibility diverges in a non-universal manner. The correlation length
critical exponent is approximately 2.3.
