-Please note that the next answer box comes to a different conclusion - and the author of this answer thinks that one is probably right-

It appears to have been at Saginaw Correctional Facility according to the testimony summarized in this document:
1997 FED App. 0264P (6th Cir.)
File Name: 97a0264p.06

Luella Burke, the warden at Saginaw Correctional Facility, testified at the preliminary injunction hearing that the visitation area there could handle 133 visitors at one time. Sally Langley, the warden at Florence Crain women's facility in Coldwater, Michigan, testified that the visitation room there had a seating capacity of 45. Both wardens, and Daniel Bolden, Deputy Director for the Bureau of Correctional Facilities, the State's third witness, testified that these rooms were not "nice places" for children. When asked to elaborate, he said: Conduct of other visitors is the primary concern in terms of sexual behavior. We've had actual fist fights in there, we've had people assault people, lot of groping and other inappropriate behaviors that go on that people were visiting, and those things were observed and viewed by these children. Rules of conduct were imposed for visitation areas, including a prohibition against touching or exposing breasts, buttocks or the genital area, but there were numerous infractions of this rule. Bolden acknowledged that prison officials had had "literally hundreds of cases regarding sexual misconduct." Warden Burke testified about a letter she had received from a visiting wife which "talked about seeing triple X stuff in the visiting room, and she was referring to the groping, genital groping, breast groping, things of that sort which, you know, does go on . . . ." Visitors were assigned specific seats or tables and were expected to remain where assigned. However, these expectations often were not realized. This was particularly true with respect to child visitors, who often left their assigned positions and mingled with other children or even with other prisoners. It was during such a wandering period that a three-year-old child was sexually assaulted by an inmate, an incident that the district judge described as a "public relations disaster" and Bolden termed "a nightmare." [paragraph breaks removed]