An investigation is underway after a woman in custody at the Weld County jail was found dead in her cell.

The Weld County Sheriff's Office says the woman was found unresponsive just before 6 a.m. Sunday. Attempts to revive her were unsuccessful, and she was declared dead at around 6:45 a.m.

The Critical Incident Response Team and the sheriff's office are both investigating, and the cause of death will be determined by the coroner's office.

Her name has not been released.