The public library is next door to the building that's being shut down, but not sure if they use our network or not, I've never been there and don't have a library card in this state.
First off, that's absolutely crazy that your college/university is taking EVERYTHING down, including fire safety, elevators and phone services. In the colleges I work with, that would be unthinkable, as there would be serious public safety issues and liabilities involved.
That said: it's unlikely that the public library, even if it's next door, is using the same network as your college or university. Public libraries usually get their internet connections from the city/county governments that fund them, OR they buy their own internet access from the local cable/phone company using state/federal grant money, often at discounted rates. This should be separate from whatever arrangement your school has (usually commercial ISP for smaller private institutions, or for bigger schools, an
Educause/
Internet2-type connection from the nearest
Gigapop provider).
Bottom line: your college/school is often funded privately or from a different branch of government than municipal public libraries, so they almost always get their internet from different sources.
Most public libraries don't require you to have a library card to get in the front door or use their internet access. in any case, you should probably give them a call, visit their website, or go there and talk to them before the internet is shut off in your building to see what they can do for you. Nowadays, most libraries are very happy to have people use their services, even if it's just to sit and use their wifi for a while.
We do have an ATT wifi, but I do not know if it will allow me to log in as a school student when school login services are down, and not sure if it is housed in the same building as school wifi that is being shut down for the day, or in the cellphone tower on campus.
If a login is required, chances are the server that checks logins/passwords will be down at the same time that everything else is out.