There is hereby created in each city, as herein defined, a public body corporate and politic to be known as “The Planned Industrial Expansion Authority” of the city; provided, however:

(1) That such authority shall not transact any business or exercise its powers hereunder until and unless the governing body shall approve, by resolution or ordinance, the exercising in such city of the powers, functions and duties of an authority under this law;

(2) That the governing body of a city shall not adopt a resolution or ordinance pursuant to subdivision (1) above unless it finds:

(a) That one or more blighted, insanitary or undeveloped industrial areas exist in such community; and

(b) That the development of such area or areas is necessary in the interest of the public health, safety, morals or welfare of the residents of such city.