Irish nationalists made an attempt to free two of their Fenian comrades by blowing up a section of Clerkenwell Prison in central London. At a quarter to four in the afternoon, a sizeable explosive device leveled a section of the prison's twenty-five foot high and twenty-seven inch thick northern wall on Corporation Road. Scores of bystanders, along with inmates of the prison, were injured and four people killed. The target had been the exercise yard but authorities had apparently been alerted and the Fenian prisoners were kept in their cells that afternoon. The escape failed and three people were almost immediately arrested. (By John Osborne)
"Chronicle of Remarkable Occurences in 1867", The Annual Register or a View of the History and Politics of the Year 1867 (London: F. & J. Rivington, 1868), 171-176.