Death of a parent (child)

The father of my children passed away unexpectedly almost 3 weeks ago. It's been a super crazy 3 weeks and horrible to say the least. Next week I have an appointment with the social security office to file for their benefits. I was wondering if anyone has experience with this, and can tell me about the benefits. I'm super anxious about them being taken care of and just wanted to hear a bit about survivors benefits for children. Thanks!