Chicago firemen strike, defying mayor's threats

Chicago's firemen went on strike Thursday depsite angry threats of dismissal by Mayor Jane M. Byrne and a court's hastily issued back-to-work order. City officials said they were trying to determine how many of the department's 4,300 firefighters were coming to work before putting contingency plans into operation. But they said there were enough firemen to keep O'Hare Airport in operation and to maintain other vital services. The firemen's union said the strike was 97 percent effective.