The fights involved inmates of one of the jail's minimum security units. Sheriff's Sgt. J.D. Nelson said the fights appear to have stemmed from an incident that happened during the inmates' scheduled outdoor yard time.
A deputy noticed that some of the bagged lunches that are distributed during yard time were missing, and told the inmates they would lose the privilege of spending time outside if the lunches were not returned.
Upon canceling yard time, inmates returned to the housing unit and a fight broke out in a common area. Nelson said that fight was stopped, but two more fights followed, one in which one of the participants suffered serious injuries and required hospital treatment.
He said each fight involved one black and one Hispanic inmate and that jail officials implemented a 24-hour lockdown to investigate the disputes, in part to determine whether there are larger racial tensions in the jail.
The lockdown, which is affecting all of the jail's 3,700 inmates, is expected to be lifted Tuesday afternoon.