Every type of legal claim has a deadline for filing suit, called the statute of limitations. The deadline starts running when the cause of action accrues. Usually when the injury happened, but sometimes when the plaintiff discovered the harm.
In Missouri, personal injury claims have a 5-year deadline. In Illinois, it's 2 years. Wrongful death is 3 years in Missouri, 2 in Illinois. Government claims have notice deadlines that are far shorter (90 days in Missouri, 1 year in Illinois) and apply on top of the standard limitations period.
Statutes of limitations are jurisdictional. A court has no authority to hear a case filed late, no matter how good the case is otherwise.