I agree with Mr. Coluccio. For example, in California, one way for the grandchildren of the decedent to be a part of the suit is if their parent (i.e., the daughter or son of the decedent) is deceased.
This attorney is licensed to practice law in the State of California. The laws of your jurisdiction may differ and thus this answer is for informational and educational purposes only and is not to be considered as legal advice. Since all facts are not addressed in the question, this answer could change depending on other significant and important facts. This answer in no way constitutes an attorney-client relationship.
A Wrongful Death suit is generally brought in the name of the Estate of the Deceased, through the appointed executor or administrator, and family/blood members are not actual parties to the litigation (except a spouse based on a claim of "loss of services"). In most states, the proceed from a wrongful death lawsuit are distributed, based upon blood line, with spouses and direct issue (children) being the first takers, subject to other conditions that must be met. It is not likely that grandchildren would be parties to the lawsuit , or that they may even share, if the spouse and child/children are still alive, but you should consult with an attorney in your area to determine what the statutes in your State spell out.