A-1 Roofing Co. entered into a written contract with Jaffe to put a new roof on the latter's residence for $1,800, using a specified type of roofing, and to complete the job without unreasonable delay. A-1 undertook the work within a week thereafter, but when all the roofing material was at the site and the labor 50 percent completed, the premises were totally destroyed by fire caused by lightning. A-1 submitted a bill to Jaffe for $1,200 for materials furnished and labor performed up to the time of the destruction of the premises. Jaffe refused to pay the bill and A-1 now seeks payment from Jaffe. Should A-1 prevail? Please explain.