Complex sentence: By the 1930s, the D&W was so weak that the C&LE, in conjunction with the Indiana Railroad, provided the financial support to keep it operating, but eventually they no longer had the funds to do so, and the D&W finally failed in 1937.
Split into simpler sentences: By the 1930s, the D&W was so weak that the C&LE, in conjunction with the Indiana Railroad, provided the financial support to keep it operating. But eventually they no longer had the funds to do so, and the D&W finally failed in 1937.