One of the first "black sites" where suspected al-Qaeda terrorists were interrogated after the 9/11 terror attacks was a secret, underground CIA prison outside Bagram Air Base in Afghanistan. The Senate Select Committee on Intelligence's critical report on the CIA tactics released Tuesday paints a stark portrait of the facility known as "The Salt Pit" in intelligence circles — a veritable dungeon where some of the most hardened al-Qaeda members were sent to be broken.

At the site, which had a classified name but is dubbed Detention Site Cobalt for the purposes of the report, detainees were kept in close, dark spaces, shackled to bars with their hands above their heads and fed "poor food." At least one detainee, accused 9-11 mastermind Khalid Sheikh Mohammed, was sent to Cobalt immediately after being captured in Rawalpindi, Pakistan, in late February 2003 and was subjected to "forced rectal feeding" within two days after his capture.

The report stated one of the primary goals of such harsh treatment was to make a prisoner feel helpless, thus making him more compliant.

Read the Senate Intelligence Committee report (PDF)

The report describes in detail the treatment of Ridha al-Najjar, who was identified by the CIA as a former bodyguard for Osama bin Laden and was the first detainee to be held by the agency at Cobalt after it opened in September 2002. Al-Najjar, who was captured in May 2002, was quickly softened up, according to the report. In an internal communiqué on Sept. 21, 2002, CIA interrogators described al-Najjar as "clearly a broken man" and "on the verge of complete breakdown" as result of isolation and severe procedures.

Specifically, according to a U.S. military legal adviser who visited the site in November 2002, "lowering the quality of his food; keeping him at an uncomfortable temperature (cold); (playing music) 24 hours a day; and keeping him shackled and hooded." In addition, al-Najjar was described as having been left hanging — which involved handcuffing one or both wrists to an overhead bar that would not allow him to lower his arms — for 22 hours each day for two consecutive days, in order to "'break' his resistance." It was also noted al-Najjar was wearing a diaper and had no access to toilet facilities.

The al-Najjar case was not unique.

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"The guards monitored detainees using headlamps and loud music was played constantly in the facility," according to the report. "While in their cells, detainees were shackled to the wall and given buckets for human waste. Four of the 20 cells at the facility included a bar across the top of the cell." Other accounts cited in the report describe detainees being shackled to the bar with their hands above their heads, forcing them to stand, and therefore not allowing the detainees to sleep.

Mohammed, known by the acronym KSM, was subjected to enhanced interrogation techniques within two days of his arrival, according to the report.

"According to CIA records, interrogators began using the CIA's enhanced interrogation techniques at Detention Site Cobalt a 'few minutes'after the questioning of KSM began," it stated. "KSM was subjected to facial and abdominal slaps, the facial grab, stress positions, standing sleep deprivation (with his hands at or above head level), nudity, and water dousing." In addition, "(the) chief of interrogations (at Cobalt) also ordered the rectal rehydration of KSM without a determination of medical need, a procedure that the chief of interrogations would later characterize as illustrative of the interrogator's 'total control over the detainee.' "

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At one point, according to an email obtained by the committee, interrogators expressed concern that his diet might interfere with the efficacy of the harsh interrogation techniques.

"He did vomit a couple of times during the water board with some beans and rice. It's been 10 hours since he ate so this is surprising and disturbing. We plan to only feed (him) Ensure for a while now. I'm head(ing) back for another waterboard session."

Treatment of the prisoners apparently went beyond the harsh techniques approved by Justice Department lawyers, the report said, because supervision at the site was entrusted to inexperienced CIA officers:

"The CIA officer in charge of DETENTION SITE COBALT, [CIA OFFICER 1], was a junior officer on his first overseas assignment with no previous experience or training in handling prisoners or conducting interrogations.

"[CIA OFFICER 1] was the DETENTION SITE COBALT manager during the period in which a CIA detainee died and numerous CIA detainees were subjected to unapproved coercive interrogation techniques."

In fact, the report noted, "A review of CIA records found that prior to [CIA OFFICER 1's] deployment and assignment as the CIA's DETENTION SITE COBALT manager, other CIA officers recommended [CIA OFFICER 1] not have continued access to classified information due to a 'lack of honesty, judgment, and maturity.'"

The U.S. military legal adviser who visited the site in November 2002 noted that the junior CIA officer designated as warden of the facility "has little to no experience with interrogating or handling prisoners."

The full Committee Study includes a CIA photograph of a waterboard at Detention Site Cobalt. There is no confirmed waterboarding at the site – though the CIA certainly did so at other secret prisons. The photo shows the device surrounded by buckets, with a bottle of unknown pink solution (filled two thirds of the way to the top) and a watering can resting on the cross beams. In meetings between the committee staff and CIA officials in summer 2013, the agency officials were unable to explain the details of the photograph, or the waterboard's presence at Cobalt. According to the report, one prisoner at Cobalt, Gul Rahman, died at the end of a Federal Bureau of Prisons delegation visit to the facility in November 2002. "An internal CIA review and autopsy assessed that Rahman likely died from hypothermia—in part from having been forced to sit on the bare concrete floor without pants," it said.

In December, the FBP delegation met with officers at CIA headquarters in Langley, Virginia, to brief the agency about the Cobalt inspection.

"During that meeting, the Federal Bureau of Prisons personnel described DETENTION SITE COBALT and stated that there was "absolutely no talking inside the facility," that the guards do not interact with the prisoners, and that "(e)verything is done in silence and (in) the dark." According to a CIA officer, the Federal Bureau of Prisons staff also commented that "they were 'WOW'ed'" at first by the facility, because "they have never been in a facility where individuals are so sensory deprived, i.e., constant white noise, no talking, everyone in the dark, with the guards wearing a light on their head when they collected and escorted a detainee to an interrogation cell, detainees constantly being shackled to the wall or floor, and the starkness of each cell (concrete and bars). There is nothing like this in the Federal Bureau of Prisons.

"They then explained that they understood the mission and it was their collective assessment that in spite of all this sensory deprivation, the detainees were not being treated in humanely (sic). They explained that the facility was sanitary, there was medical care and the guard force and our staff did not mistreat the detainee(s)."