Extremely unlikely. If you search for the term 'no duty to protect', or read Warren v. District of Columbia, DeShaney v. Winnebago County and Castle Rock v. Gonzales you will find more than you wanted to know on the concept that the police/state have no particular responsibility to any individual. It's why you have a duty to your family to have some effective form of self defense available, at all times, because the police aren't going to be held responsible even if they never show up at all.
The two most likely areas for it to happen are cities on the edge of financial collapse like Detroit, and rural areas. You can find average emergency response times for Detroit pretty easily, it can be tough in rural areas too - even in MA. If you dial 911 in my town looking for police, you're hoping that one of the 4 part time officers who all have full time jobs somewhere else can answer the beeper, although they can take a couple minutes to get their shit together and out the door. If they aren't around, the call gets bounced to the local state police barracks. They might have 5 or 6 troopers working, but even if one of them is sitting there bored when the call comes in, he's still 18 miles away. Since they cover IIRC 14 towns, there's a much better chance he's working somewhere else, which might be closer or further from you. In any case, he doesn't know the town that well so finding you can be challenging.
You are on your own. You are responsible for the security and safety of yourself and your family.
