text: As the work stoppage spread, the carpenters' union's contract with the construction companies expired on May 30.The employers declared on June 12 that they would no longer adhere to any closed shop agreements with the carpenters, and instead would impose the open shop and employ any carpenter (union or non-union) in order to finish the work on existing construction projects. The construction unions declared they would pull every worker off every job if non-union construction laborers were hired, and the D.C Metropolitan Police Department made preparations to patrol streets and job sites to prevent any violence from erupting. Non-union workers were hired, and the carpenters' union went on strike at all job sites throughout the city amidst fears that the carpenters might strike all federal construction projects nationwide. Three union members were injured on June 13 as picketers clashed with security guards hired by the employers. But the strike did not spread to the other unions, and the Washington Building and Construction Trades Council and D.C. Commissioner George E. Allen attempted to mediate an end to the strike. 