Solitary Confinement at Alcatraz: D Block and the Dark Cells

Discipline at Alcatraz had a clear top tier. This page looks at D Block, officially the Treatment Unit, and at the isolation cells in its lower level that inmates called dark cells.

D Block after 1940

When D Block was remodelled in 1940, it became the Treatment Unit and was walled off from the rest of the cellhouse. Unlike the other blocks, where cells sat back to back, a D Block cell had a wall behind its utility corridor. On the ground level, called “the flats”, a door could only be opened after the officer in the gun gallery had unlocked it for the D Block guard.

Residents stayed in the block all day. When the rest of the population went to the dining hall, D Block men ate in their cells, with trays passed through a slot. A separate shower area was built at the west end so they never mixed with other inmates, and recreation was scheduled at different times as well.

The dark cells

The harshest feature was the Special Treatment Unit on the flats, whose cells were nicknamed dark cells. Each one had two doors. The inner door was steel bars with a food slot, as elsewhere in D Block, and the outer door was solid, with a shuttered glass panel that a guard could open to check on the occupant. The light was controlled by staff, not the inmate.

Five of these cells had a sink, a toilet and a bed, though the mattress was handed in at night and removed in the morning. The sixth, called the strip cell, had none of that, only a hole in the floor that a guard could flush. It was usually for men who were wrecking their plumbing. Because the conditions were so severe, regulations limited how long a person could be kept in one.

How someone ended up there

A trip to a dark cell normally followed violence among the general population or a behaviour problem in D Block. Someone already in a punishment cell has little left to lose, so offences such as throwing an object at an officer or smashing fixtures were what moved him downstairs.

If conduct did not improve, staff could tighten conditions. They could withhold the night mattress, keep the light off or on, or serve meals that had been blended into liquid. As a last step a man might spend a few days in the strip cell. The response followed behaviour: once it improved, he would be moved up to the second tier of D Block.

How long it lasted

After a violent outburst, release usually came in three or four days, moving first to an ordinary Treatment Unit cell to make sure the person had settled before returning to the general population. Someone who believed he could outlast the system by serving a couple of weeks and then behaving the same way could be sent straight back. For most of the federal period, the limit for dark cell punishment was 19 consecutive days.

Who decided

An inmate who broke a rule was “shot”, in inmate slang, meaning he was written up. A disciplinary board, typically a lieutenant and senior officers, then heard the case. Penalties for minor matters might be loss of privileges, for example no family visits for a year. More serious breaches, especially assault or attempted escape, could mean loss of good-time credit and time in the Treatment Unit.

Not everyone in D Block was there for punishment. Many men on the top tier were separated for their own safety, because they had done something that made the main population dangerous for them. Informers and former police officers also used it as protective custody.

Why the cells were larger

The oldest cells were built by the Army according to War Department rules for military prisons. When the Justice Department sought bids for the new D Block cells in 1939, they had to meet civilian prison standards of that year, which had changed and required more space.

The extra room did little to make life easier. Men stayed in these cells nearly 24 hours a day, with no visitors, magazines or work, limited mail and only a few hours of recreation each week. It usually took little time before they were asking to write a note of apology and return to the main population.

See also minimum privileges, maximum custody and the 1946 riot.

A last word on isolation

Isolation was a tool of last resort. Most inmates never saw the dark cells, and many of those who did were back in the main population within days. The system relied on the idea that the prospect of D Block was itself a deterrent, and the stories told about it, sometimes exaggerated, reached every man in the cellhouse. This is one reason why debates about the treatment of inmates at Alcatraz, noted on the page about how conditions changed, have continued long after the prison closed.