  Isolated Cohen-Macaulay codimension 2 singularities share many common
features with isolated complete intersection singularities, but they also
exhibit some striking new behaviour. One such instance was recently observed by
Damon and Pike in their study of the vanishing topology and Euler
characteristic, where they took this class of singularities as examples. In
this article, we explore their findings further by determining the Betti
numbers explicitly and explain the new phenomena. An important tool here is the
Tjurina modification relating a Cohen-Macaulay codimension 2 singularity to a
finite number of complete intersection singularities.
