Accumulations of waste paper, hay, grass, straw, weeds, litter or combustible or flammable waste or rubbish of any kind shall not be permitted to remain upon any roof or in any court, yard, vacant lot or open space. All weeds, grass, vines or other growth, when it endangers property, or is liable to be fired, shall be cut down and removed by the owner or occupant of the property it is on.