in the fort to confine the prisoners (including Holwell), at , the jailers stripped the prisoners of their clothes and locked the prisoners in the fort's prison—"the black hole" in soldiers' slang—a small room that measured . The next morning, when the black hole was opened, at , only about 23 of the prisoners remained alive. Historians offer different numbers of prisoners and casualties of war; Stanley Wolpert estimated that 64 people were imprisoned and 21 survived. D. L. Prior estimated that 43 men of the Fort-William garrison were either missing or dead, for reasons other than suffocation and shock. Busteed suggests that the many non-combatants present in the fort when it was captured make infeasible a precise number of people killed. Regarding responsibility for the maltreatment and the deaths in the Black Hole of Calcutta, Holwell said, "it was the result of revenge and resentment, in the breasts of the lower Jemadars (sergeants), to whose custody we were delivered, for the number of their order killed during the siege." Concurring with Holwell, Wolpert said that Siraj-ud-Daulah did not order the imprisonment and was not informed of it. The physical description of the Black Hole of Calcutta corresponds with Holwell's point of view: Afterward, when the prison of Fort William was opened, the corpses of the dead men were thrown into a ditch. As prisoners-of-war, Holwell and three other men were transferred to Murshidabad. Imperial aftermath The remaining survivors of the Black Hole of Calcutta were freed the next morning on the orders of the nawab, who learned only that morning of their sufferings. After news of Calcutta's capture was received by the British in Madras in August 1756, Lieutenant Colonel Robert Clive was sent to retaliate against the Nawab. With his troops and local Indian allies, Clive recaptured Calcutta in January 1757, and defeated Siraj ud-Daulah at the Battle of Plassey, which resulted in Siraj being overthrown as Nawab of Bengal and executed. The Black Hole of Calcutta was later used as a warehouse. Monument to the victims In memoriam of the dead, the British erected a 15-metre (50') high obelisk; it now is in the graveyard of (Anglican) St. John's Church, Calcutta. Holwell had erected a tablet on the site of the 'Black Hole' to commemorate the victims but, at some point (the precise date is uncertain), it disappeared. Lord Curzon, on becoming Viceroy in 1899, noticed that