there, all wearing TWU buttons, began a sitdown strike, seizing control of the plant until management reinstated the workers it had fired. Other BMT employees established a picket line outside the plant and defended it from the efforts of the police to retake it, while helping to supply the workers inside with food supplied by the Retail Clerks union. The union then gave the BMT a deadline: reinstate the three fired engineers by 6:00 a.m. the next day or they would shut off the electricity for the system, affecting 2,400,000 BMT riders. The BMT folded a half-hour before the deadline and agreed to meet to discuss the union's demand for recognition as the exclusive bargaining representative of its employees. While the union did not win that demand, its victory at Kent Avenue established it as the de facto representative of these workers and, in time, all of the BMT's employees. Also, this marked the beginning of the end of the harsh treatment of transit workers in the nation's largest city. The TWU severed its relations with the Machinists and joined the CIO as a national union on May 10, 1937. Quill had already replaced O'Shea as President of the union, while Santo became its Secretary-Treasurer. The union won an NLRB-conducted election among the IRT's 13,500 employees by a landslide in May, then grew to 43,000 members by June of that year, as it now had more than half of the employees of all of the three subway lines, several bus and streetcar companies and seven major taxicab companies signed up as members. The union also won recognition for most of the BMT's employees, although they found this more difficult: they were not able to displace either the Brotherhood of Locomotive Engineers or the Brotherhood of Railway Signalmen in the units in which they were the established representative, and took two elections to win among the ticket-sellers. The union had grown from 8,000 to 30,000 members in a year. Public ownership The union soon faced a serious challenge to its newly-won status as representative of the employees of the IRT and BMT when the City bought those lines in 1938. The union had already discovered that the City Board of Transportation, which ran the smaller Independent Subway System (IND), was as dismissive of unions as the private lines, even though two of the three members had union backgrounds before they entered