It will fail. Numerous people have sued the police for not protecting them and the SC has ruled that the police have no duty to protect you.
Yep...this as settled as any court precedent. The lawsuit should not survive preliminaries.
"Dial 911 and Die" discusses the history of this Supreme Court decision. Local law enforcement is under no obligation to provide any one protection.
Of course, when the State disarms potential victims, there must be some implied obligation.
The police were under contract to protect the school, this creates a special case that is different from protecting the general public. Basically as I understand the law, the police are not obliged to protect any specific person, unless they have formed a contract with that person.
Ya beat me to it, but I did link to a SC case.