according to an official report from prr dated december 1, 1945, which is now stored in the hagley museum and library, s1 #6100 was awaiting engine truck repairs at crestline. it was expected to be returned in service after a few days. this is one of a solid proof that s1 was still in service at least until december 1945. at the time, at least 13 t1 4-4-4-4 were already put into service.