to possibly oust TWU in favor of the more pliable PRTEU. The PTC was aware that the Smith–Connally Act forbade strikes harming war production and that if, with a contract impasse, TWU itself had initiated a contract strike, the union might have been tossed out. This analysis of the situation was shared later by several historians, particularly by James Wolfinger. Another historian, Alan M. Winkler, also had a largely negative view of the company's role in the conflict and concluded that PTC management, while not overtly conspiring with the strikers, reacted feebly to the strike and tried to opportunistically exploit the situation and the racist attitudes of many white workers for their own purposes. The leaders of the strike, including McMenamin and Carney, were charged in federal court under the Smith–Connally Act; some thirty strikers were also indicted later. The federal grand jury was convened on August 9 and heard testimony for two months. However, the grand jury returned inconclusive findings; their report stated that most of the striking workers knew nothing about the strike at the start, and blamed a few instigators for escalating the situation, but did not detail the instigators' activities. The report was also critical of the PTC's response to the strike, characterizing it as inadequate and ineffective. The government dropped its charges against the defendants on March 12, 1945, with most of them pleading nolo contendere and receiving a fine of $100 each. As labor historian James Wolfinger observed, the strike "demonstrated the profound racial cleavages, that divided the working class, not just in the South but across the nation". Although brief, the Philadelphia transit strike of 1944 had significant negative impact on the war effort, resulting in a loss of four million work hours in war plants alone. The War Manpower Commission estimated that the Philadelphia strike cost the nation's war production the equivalent of 267 Flying Fortresses or five destroyers. Malcolm Ross later characterized the strike as "the most expensive racial dispute of World War II". The strike also exposed the limitations of the FEPC's power. The FEPC did not possess the final authority to enforce its decisions and only the executive intervention of the President made the resolution of the dispute possible. Nevertheless, the strike demonstrated that a combination of black activism, particularly by the NAACP, together with resolute federal policies, were able to break long standing racial barriers in employment. See