Section 770. Grounds for the proceeding

1. One-third or more of the tenants
  occupying a dwelling located in the city of New York or the commissioner
  of  the  department  of the city of New York charged with enforcement of
  the housing maintenance code of such city, or in the counties of Nassau,
  Suffolk, Rockland and Westchester may maintain a special  proceeding  as
  provided  in  this  article,  upon  the ground that there exists in such
  dwellings or in any part thereof a lack of heat or of running  water  or
  of light or of electricity or of adequate sewage disposal facilities, or
  any  other  condition  dangerous  to  life,  health or safety, which has
  existed for five days, or an infestation by rodents, or any  combination
  of  such  conditions; or course of conduct by the owner or his agents of
  harassment, illegal eviction, continued deprivation of services or other
  acts dangerous to life, health or safety.
    2. If  the  proceeding  is  instituted  by  the  commissioner  of  the
  department  of  the  city  of  New  York charged with enforcement of the
  housing maintenance code of such city, one-third or more of the  tenants
  may,  at  any  time  thereafter during the pendency of the proceeding or
  after final judgment pursuant to section seven  hundred  seventy-six  or
  seven  hundred  seventy-seven of this article, petition for substitution
  of  themselves  in  place  and  stead  of  such  commissioner  of   such
  department.  Such substitution shall be ordered by the court unless good
  reason to the contrary shall be shown.