I did not come across the obits yet but if you check intohttp://fultonhistory.com/Fulton.html
you will see many articles about the Pettengill family.His bbrother Leslie obit.Visiting his sick mother. Lots of traveling.
Mentioned Harriet as the mother so I looked into 1892 census. William and Harriet Pettengill were Walters parents.
He had many brothers and sisters.