The events that led up to the bombing started with the arrest, in November 1867, of Ricard O'Sullivan Burke, a senior Fenian arms agent who planned the "prison-van escape" in Manchester a few months earlier. O'Sullivan-Burke was subsequently imprisoned on remand in the Middlesex House of Detention, Clerkenwell. On 13 December an attempt to rescue him was made by blowing a hole in the prison wall. The explosion was seriously misjudged; it demolished not only a large section of the wall, but also a number of tenement houses opposite in Corporation Lane (now Corporation Row) that killed twelve people and wounded up to a 120 more.