Word will not correct them because all are correct grammatically but they do have different meanings. But this is one of those gray areas in English. Do the 's apply to everything behind it? Is it street or are we combining them into streets?
10th, 11th, and Front Street's Fund Raiser
- This is the one I recommend because what we're saying here is 10th Street's fund raiser, 11th street's fund raiser, and front street's fund raiser. It means that these streets are in possession of this fund raiser.
10th, 11th, and Front Streets Fund Raiser
- This one is probably not what you're looking for. This has no possession of the fund rasier because there's no apostrophe.
10th, 11th, and Front Streets' Fund Raiser
- This is okay as well because what we're saying is that these streets are combined and they have possession of the fund raiser. But I recommend the first just because it's less likely to attract attention.