You will have several problems, any one of which could make it impossible for you to win.1) First and foremost, the statute of limitations, or time within which you must start or file a lawsuit in your state for a matter like this (one involving a written agreement, like an insurance policy) is only 5 years. If this is now "5 years later," then depending on the exact time frame, it may now be too late to sue; once the statutory period has expired, you can no longer bring a lawsuit2) Second, to win, you'd have to prove in court by a "preponderance of the evidence" that the damage was caused by the tornado and that they should have paid. After 5 years, you may not be able to, even with the contractor's help, provide sufficient evidence to prove that (i.e. may not be able to provide sufficient documentary evidence or credible testimony, given the passage of time, so as to convince the court).