  Crack nucleation is a ubiquitous phenomena during materials failure, because
stress focuses on crack tips. It is known that exceptions to this general rule
arise in the limit of strong disorder or vanishing mechanical stability, where
stress distributes over a divergent length scale and the material displays
diffusive damage. Here we show, using simulations, that a class of diluted
lattices displays a new critical phase when they are below isostaticity, where
stress never concentrates, damage always occurs over a divergent length scale,
and catastrophic failure is avoided.
