If the owners referred to in 7-12-4147 fail to elect to take the work, to enter into a written contract for the work within 3 days, or to commence the work within 15 days after the date of the written contract and to prosecute the contract with diligence to completion, the city council shall enter into a contract with the original bidder to whom the contract was awarded at the prices specified in the bid.
§ 7-12-4148, MCA