This story was originally published May 16 at 2:30 p.m.Sinéad O'Connor has reportedly gone missing in Chicago.Police confirmed to the Chicago Tribune that O'Connor was last seen early Sunday morning when she went out for a bike ride. After she didn't return, local authorities sent out a "check-for-well-being alert" that afternoon."A caller has expressed concern for her well-being, and no other information is available at this time," a statement from the police said.O'Connor was reportedly last seen riding a Raleigh motorized bicycle with a pink basket. She was wearing a black parka, black leather pants, and a sweatshirt that says "Ireland" on the back.Before she was reported missing over the weekend, O'Connor posted a note on Facebook to her 28-year-old son, Jake. In it, she asked him to appear in court and "take custody" of his 12-year-old brother Shane, for whom O'Connor is currently in a custody battle with ex Dónal Lunny.In the note to Jake, O'Connor wrote, "Do not abandon your brother or any other of my babies again. What you have done to your brother and your mother is LITERALLY criminal."This followed an open letter the singer posted to Shane on Friday, urging him to take charge of the custody battle by getting a solicitor who can tell the court that he wants to be with his mom but is being prevented from doing so. "Your mother is being bullied so badly by Tusla she can't manage your release," O'Connor wrote.In the letter, the 49-year-old also told Shane, "I have to back off because they are hurting me so badly I get unwell again if I go near them."