Class action lawsuits are composed of groups of people with the same or similar injuries and/or damages, stemming from the same source. The cause of the injury may be a specific event or incident: contamination from a toxic substance, material or structure; faulty medical treatment or use of the same defective product, drug or device. Usually, the injured parties have sustained fairly minor injuries. Therefore, by combining the individual claims into one action, the claim becomes more practical for the plaintiffs and for the court system. It is more cost effective to litigate all the claims at one time, since the costs of litigation will be paid by the group, not by an individual plaintiff. Additionally, by combining the smaller claims together, they add up and may gain strength in proving the plaintiff??s case to the court.