Section 706. When surviving or remaining fiduciary may act; when successor must be appointed 1

Where one of two or more fiduciaries dies or is removed  or  where
  letters  issued  to one of them are revoked, a successor to the deceased
  fiduciary or to the one who has been removed or whose letters have  been
  revoked  shall  not  be  appointed,  except  where  such  appointment is
  necessary in order to comply  with  the  express  terms  of  a  will  or
  lifetime  trust  instrument; but the others may proceed and complete the
  administration of the estate pursuant to the letters or  lifetime  trust
  instrument  and may continue any action or special proceeding brought by
  or against all.
    2.  When all the persons to whom letters have been issued die or where
  letters issued to all of them have been  revoked  by  a  decree  of  the
  surrogate's court, or, in the case of a lifetime trust, when all persons
  serving  as  trustee  die  or are removed, without any successor trustee
  having been effectively appointed pursuant to the terms of the  lifetime
  trust instrument, that court has, except in a case where it is otherwise
  specially  prescribed  by  law, the same power to appoint a successor to
  the person or persons whose powers have ceased as if the letters had not
  been issued or as if no appointment had been made.   The  successor  may
  complete  the administration of the estate committed to his predecessor,
  he may continue in his own name a civil action or proceeding pending  in
  favor  of his predecessor and he may enforce a judgment, order or decree
  in favor of the latter.