Can you clarify who was slain? Was this a funeral?-LFD
From the Wiki links - enough background to get the gist:"On 27 February 1861 a Warsaw crowd protesting against the Russian rule over Poland was fired upon by the Russian troops. Five people were killed. "and "By February 27, 1861, national feeling had risen so high in Poland that the government called out the military; five victims fell in the Krakowskie Przedmieście, Warsaw, and their burial and the memorial service were turned into patriotic demonstrations, in which, for the first time, "the Old Testament Brethren" of the Poles participated as a community. Though it was Sabbath, three rabbis, including Jastrow, joined the funeral cortège; at the memorial service in his synagogue, also on a Sabbath, Jastrow preached his first Polish sermon, which aroused such great enthusiasm that on Sunday his auditors reassembled and took it down at his dictation. Circumventing the censor, they distributed ten thousand manuscript copies within a week."
Rev. Dr. M. Jastrow was giving a memorable Thanksgiving sermon in English just a few years later in America.http://books.google.co.il/books/about/Sermon_delivered_in_the_Synagogue_Rodef.html?id=SH1wyYdfQ-IC&redir_esc=y