A motor vehicle collision occurred on the southbound I81 near the Spencer St ramp (Exit 21) in Syracuse, NY. The incident involved an overturned vehicle that blocked all lanes of 81 South just past Spencer St. The traffic was backed up for over a mile, and Syracuse Police had to shut down the entrance ramps to the highway. The authorities have not confirmed any injuries at this time. We advise drivers to avoid the area and seek alternative routes until the situation is resolved. 

Update 5:10PM: Right lane re-opened and traffic starting to clear.

Update 5:40PM: All lanes reopened.