To clarify the answers to Chuck's questions:
The B&B branch originated as an independent railroad--and narrow-qauge at that--which the MONON acquired around 1895 to provide access to the coalfields west of Bedford. The MONON almost immediately standard-gauged the line. The line experienced many derailments due to its narrow right-of-way and it's use as a coal-hauling route became redundant just 15 years later when the MONON built its I&L "Pumpkin Vine" line into the same area.
As for the Indianapolis branch, the MONON did not end freight service on it--L&N did. MONON did end all passenger service on the branch though, about 12 years before the merger. L&N slowly abandoned the line piecemeal, starting from the Indy end.