On Extremal Contractions from Threefolds to Surfaces: the Case of One   non-Gorenstein Point
  Let $f\colon X\to S$ be an extremal contraction from a threefold with only terminal singularities to a surface. We study local analytic structure such contractions near degenerate fiber $C$ in the case when $C$ is irreducible and $X$ has on $C$ only one non-Gorenstein point. 
Yuri G. Prokhorov