ר' פנחס הערצקא ז"ל.

ברם זכור אותו האיש לטוב                                                                     

In most Kehilos & Shuls at the end of the קינות, an additional קינה was added lamenting the Holocaust.

This Minhag is only about forty years old.

It all started with one man, a Holocaust survivor, ר' פנחס הערצקא ז"ל. He was a חשובע בעל הבית and a תלמיד חכם, a Pressburger Yid who lived in Brooklyn.  

Mr. Fritz Hertzka was bothered that on Tisha B'av in addition to lamenting the Churban Habayis we lament other Churbonos (crusades etc.)  yet, the greatest Churban of Klall Yisroel since the Churban Bais Hamikdash is totally ignored.

He went to all the Gedolim & Rabonim with his idea of adding a קינה for the Holocaust. He contacted hundreds of Rabonim to seek their support. I have seen a letter he sent to my father ע"ה asking him to speak to a certain Rav in Montreal to convince him to agree to this concept.

In the beginning, some Gedolim were not so eager to go along with his idea. Mr. Hertzka didn't take no for an answer. He managed to convince them and eventually most Gedolim agreed to add a קינה lamenting the Holocaust.

The special  קינה for the Holocaust was added only because of one man, Mr. Fritz Hertzka ע"ה 

                                                                    יהא זכרו ברוך