What is the name of your state? Pennsylvania.

In some or all cities, one is required by directive or law to maintain their sidewalks. This includes removing ice and snow and general upkeep. But there seems to be mixed opinions on who owns the sidewalks in front of our homes.
Some say the sidewalks are theirs; others say the city has easement rights and you still own it and the rest say the city owns it.
I measured my property (cannot say it is accurate) and the length appears to end at my brick retaining wall and the ownership of my sidewalk appears to be in doubt.
So assuming the city owns the sidewalk, can one still be held liable for any accidents that occur on the sidewalk. If so, why is this?