Below details based on testimony of the family and as printed in the book: The Unfinished Diary: A Chronicle of Tears.
He was buried in the Ostrowiec cemetery, but during the war/post war period, his matzeva was removed from the grave site and later found among hundreds of broken matzevot in the cleaning up of the cemetery about 50 years after the war. Today it can be seen in the lapidarium in the Ostrowiec cemetery hill.
Chaim Yitzchok Wolgelernter
Yechiel Issomor's grandson Chaim Yitzchok Wolgelernter, although living elsewhere, moved at age 17 to learn at the yeshiva of the Ostrovtzer Rebbe at the time, Rabbi Yechezkel Halstock, son of Rabbi Meir Yechiel Halstock.
Read more about him and the Wolgelernter family.