2:05 PM UPDATE:
The accident has been cleared, but the DOT reports traffic is backed up on the northbound side from Exit 16 in Norwalk all the way to Exit 3 in Greenwich.
An overturned vehicle is backing up traffic on Interstate 95 in Norwalk, according to the state Department of Transportation.
The accident occurred on the northbound side between exits 16 and 17. The right lane is closed.
There is no estimate from the DOT on when the accident might be cleared. It was reported at 12:20 p.m.
As the screenshot from Google Maps shows, traffic is backed up in both directions around the accident.