Danbury Branch Siding in SoNo

I recently visited S. Norwalk and noticed that there are two sidings on the Danbury Branch. The first starts just north of Marshall St and reconnects to the main track just south of Science Rd. The second branches off from the first under I-95 and runs to the south. Questions:
1. Where does the second siding end and does it reconnect to the first?
2. What is it used for?

its the remains of DOCK yard, it is used to store MofE equipment, build switches etc. the north switch near Marshal str is no longer in service. just part from I-95 to just before mainline