Prisoners in California’s Bay Area are participating in a hunger strike. The strike started in July, when prisoners in Pelican Bay State Prison decided to have their voices be heard outside prison walls. The inmates say they are facing cruel, inhumane and even torturous conditions in the prison’s Security Housing Units (SHU) and Administrative Segregation Units (Ad-Seg)

At least 12,000 inmates across California have participated in the hunger strike. Over 3,000 California prisoners held in out-of-state facilities in Arizona, Mississippi and Oklahoma have also refused food.

“This is the largest prisoner strike of any kind in recent U.S. history,” said Ron Ahnen of California Prison Focus. “The fact that so many prisoners are participating highlights the extreme conditions in all of California’s prisons as well as the historic opportunity the state has been given to make substantial changes to SHU and Ad-Seg policies.”

Family members of striking SHU prisoners reported that their visits were denied by the California Department of Corrections and Rehabilitation (CDCR), which cited security concerns.

“A number of family members received notice that they were not going to be allowed to see their loved ones as long as the strike continues,” said Dolores Canales, who has a son in the Pelican Bay SHU. “Denying visits only heightens the isolation that the prisoners and family members experience, especially at this critical time.”

Since the hunger strike began, deaths have been reported in the prisons, including one in November that had a family calling on President Barack Obama for answers. Inmate Hozel Blanchard, who was at Calipatria State Prison reportedly died in Ad-Seg. The CDCR claimed Blanchard’s death and two others’ were suicides.

Activists say that inmates in Ad-Seg are so isolated that prison guards can do anything they want without anyone knowing. Blanchard had served 17 years in prison at the time of his death.

“Hozel had explained to us in his letters that he was a part of the hunger strike, and his reason for doing so was because of false accusations resulting in two additional charges that were recently filed against him,” said his mother, Yolanda Moore, in a letter to the president. “Hozel feared for his life and made sure that he got word to us that he no longer felt safe.”