Financial support for 3 teenagers

Hi my name is Joan Lillya aunt of Eric Kates...Eric unexpectedly passed away on July 21st. He was  the father of 3 children who has been left to be cared for by their elderly grandfather. My brother an his wife received residential custody while the children are in school their mother is from Columbia an her primary resident is in Columbia...This is sad their mother has not help with any support in a long time, my brother has been supporting them on his own..Eric did not have a life insurance policy or any other account that would have helped provide care.  I am trying to help cover the initial expense for funeral cost and to help provide for the children upcoming school supplies an clothing. They r 17 an 14 years old so any help would be greatly appreciated.