street water main knob broke - whats next?

[Bill McCasky]

Searching didnt turn up much - 

I have a 4-plex in '04 - tried to cut the water at the street for some upgrades and the top of the shutoff vale snapped off. See it in red in picture.  The bldg was built in '72 so its likely almost 50 years old.   

Am I responsible for these repairs? (The shutoff valve is on street side)

How long does this take to get fixed from the city?  What if i hire a plumber?

Whats the cheapest way to get this remedied?  Fastest?  

If I call the city - how do I phrase this in the best way possible for myself?

Whats your experience with anything similar to this?    Any tips?

Image attached for reference/example, only: