  Simulations and theory are presented of an ITER locked mode thermal quench
(TQ). In present experiments, locked mode disruptions have a long precursor
phase, followed by a rapid termination and thermal quench, which can be
identified with a resistive wall tearing mode (RWTM). In ITER, the RWTM will be
slowed by the highly conductive vacuum vessel. The rapid termination might be
absent, and the plasma could remain in the precursor phase. If the edge
temperature is in the collisional regime, the TQ would proceed on a long
timescale, limited by the RWTM to almost $100ms.$ This is an important self
mitigating effect.
