According to TMZ, singer Sinead O'Connor has been reported missing after going on a bike ride in Chicago Sunday morning and failing to return.
The site reports that O'Connor has been classified "missing suicidal" by Chicago police, who reportedly received a 911 call from a concerned friend of Sinead's this morning.
O'Connor has a history of erratic behavior, and troublingly, she's displayed suicidal tendencies in the past.
Just last year, O'Connor left a suicide note for her family to find, and was eventually hospitalized to be treated for a number of mental health issues.
While she was reportedly stable for several months after being released, O'Connor's condition seems to have worsened recently.
Those closest to O'Connor say she's been deeply disturbed ever since the death of Prince, her longtime friend and mentor.
Her mourning was apparently exacerbated by O'Connor's bizarre public feud with Arsenio Hall, whom she claims provided drugs to the late pop star.
Currently, O'Connor is being sued by Hall, after she publicly blamed the comedian for Prince's death.
There is no word on the specifics of O'Connor's disappearance, but those closest to the 49-year-old are said to be deeply concerned.
A police bulletin reported that O'Connor was dressed in a black parka and black leather pants, and riding a motorized bike.
Insiders say the singer is not familiar with the suburb of Wilmette, where she was reportedly last seen.
While the neighborhood where she is believed to have disappeared is a relatively safe one, authorities and loved ones are reportedly concerned about O'Connor's capacity for self harm.
The police bulletin indicates that anyone who sees O'Connor should contact the Chicago PD.
We'll have further updates on this story as more information becomes available.
UPDATE: O'Connor has reportedly been found safe. Police have not released any further details about her condition.