LOS ANGELES — For Carlos Inzunza, the image will be forever seared in his mind: a cellmate hanging by a twisted sheet at the Adelanto immigrant detention center in Southern California. The noose was cut loose by a guard just in time.

“There was a lot of despair over there,” said Mr. Inzunza, 43, who spent seven months at the center in the southwestern Mojave Desert last year. “I was in a cell with five other people. Two of them were anxious and wanted to commit suicide.”

Migrants imprisoned at the country’s largest privately-run adult immigration detention facility manage to regularly hang “nooses” fashioned from bedsheets in their cells, according to a report by federal inspectors made public on Tuesday.

During an unannounced visit in May, federal inspectors found that 15 out of 20 cells they inspected had what they described as nooses made of braided bedsheets hanging from vents, the Department of Homeland Security’s Office of the Inspector General reported in a 15-page “alert.”