A lot has to blame on the 1938 Hurricane. During that storm numerous bridges were washed out along the Hartford-Providence line. Towns like Windham, Chaplin, and Killingly all lost passenger service after this.
I don't know how many rail fans we have in here, but Willimantic used to be one of the largest centers of rail activity in New England and the Northeast. At one point you could hope on a train to Hartford, Providence, New Haven, New London/Norwich, and Boston.
The old rail line which ran from Hartford to Willimantic is now a nature walk. Most if not all the bridges were made smaller for pedestrians. In the 70's there was talk of rebuilding the line from Willimantic to Hartford, and then once again in the 90's there was talk but nothing happened. The Hartford area could support some kind of Regional train service. It did in the past, however that was when the car was less of a need.
If done right, there could be service like mentioned before from Hartford to Willimantic on the old lines. The only thing needed to be rebuilt would be the bridges, the most expensive part. A line from Willimantic to New London is still in use, but there hasn't been passenger service there for decades, the last being Amtrak's Montrealer which ended service to Windham in the mid 90's.