§ 78. Repairs. 1. Every multiple dwelling, including its roof or
roofs, and every part thereof and the lot upon which it is situated,
shall be kept in good repair. The owner shall be responsible for
compliance with the provisions of this section; but the tenant also
shall be liable if a violation is caused by his own wilful act,
assistance or negligence or that of any member of his family or
household or his guest. Any such persons who shall wilfully violate or
assist in violating any provision of this section shall also jointly and
severally be subject to the civil penalties provided in section three
hundred four.

2. Whenever, the light, ventilation, or any matter or thing in or
about a multiple dwelling or part thereof, or in or about the lot on
which it is situated, is in the opinion of the department in a condition
or in its effect dangerous to life or health, the department may order
or cause any such light, ventilation, matter or thing to be repaired or
improved or, as provided in section three hundred nine, take such other
action as it may deem necessary to remove such danger to life or health.