Pam...
I think you know I work as a Crisis Interventionist with the local PD. I don't have a lot of resources for other states, but I do have this:
http://211.org/
click on "find your local 211 call center" and then enter the zip code where they live. It will give you a BUNCH of resources, including contact info for Survivors of Suicide. I cannot say enough how much I encourage the enire family to seek help in dealing with this loss.
It is normal that the nephew is angry... it's part of the grieving process. The hard part is learning to direct that anger in a healthy way, not towards other family members. There are many, many free support groups out there... with other people who have experienced the loss of someone they love to suicide.
Guilt is a normal part of this process as well... but I can tell you one thing. When someone decides, truly decides that they're done, and they're going to commit suicide, there is NOTHING anyone can do to stop them. At that point, it's just a matter of them finding the privacy needed to make it happen and there is nothing anyone can do. You cannot stay with them 24/7. The one thing you can say to your family, with total conviction is this: It's not your fault. It was his decision and not in your control.
No matter how many times they try to take the blame, repeat that phrase OK? Because it's the truth.
Hugs my friend. I can't begin to imagine.